Shakun Redux: Master tricksed us! I told you he was tricksy!

The quote above is from Lord of the Rings, an exchange between Gollum and Smeagol, and it encapsulates my latest results from looking into the Shakun 2012 paper, “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” (paywalled, at Nature hereinafter Shakun2012). I discussed the paper in my post “Dr. Munchausen Explains Science By Proxy“. Please see that post for the underlying concepts and citations.

When I left off in that post of mine, I had investigated each of the 80 proxies used in Shakun2012. I plotted them all, and I compared them to the CO2 record used in their paper. I showed there was no way that the proxies could support the title of the paper. Figure 1 recaps that result, showing the difficulty of establishing whether CO2 leads or lags the warming.

Figure 1. All proxies (green dots) from Shakun2012 (Excel spreadsheet). CO2 values digitized from Shakun 2012 Figure 1a. There is pretty good agreement between the warming and the changes in CO2.

Note that the proxies say the earth generally warmed from the last ice age, starting somewhere about 15,000 BC, and the warming lasted until about 9,000 BC. Since then, the proxies have the greatest agreement (darkest green). They say that the globe generally cooled over the length of the Holocene, the current interglacial period since the last ice age.

Today I was thinking about that single record that they used for the CO2 changes. I got to wondering what other ice core CO2 records might show about the change in CO2. So I went and downloaded every ice core CO2 record that I could find that covered the time period 26,000 BC to modern times. I found a number of ice core records that cover the period.

Then I collated all of them in Excel, saved them as a CSV file, opened the file in R, and plotted every ice core CO2 record that covered the record from 26,000 BC up to the present. I standardized them over the same period covered by the Shakun2012 CO2 data. There was excellent agreement between the Shakun2012 data and the ice core records I had downloaded … but there was also a surprise.

Figure 2 shows the surprise …

Figure 2. As in Figure 1. Black circles show Shakun2012 CO2. Additional colored dots show the ice core CO2 records which have data from 26,000 BC to the present.

Dang, I didn’t expect that rise in CO2 that started about 6,000 BC. I do love climate science, it always surprises me … but the big surprise was not what the ice core records showed. It was what the Shakun2012 authors didn’t show.

I’m sure you can see just what those bad-boy scientists have done. Look how they have cut the modern end of the ice core CO2 record short, right at the time when CO2 started to rise again …

I leave the readers to consider the fact that for most of the Holocene, eight centuries millennia or so, half a dozen different ice core records say that CO2 levels were rising pretty fast by geological standards … and despite that, the temperatures have been dropping over the last eight millennia …

And I leave everyone to ponder how far climate “science” has fallen, that a tricksy study of this nature can be published in Nature, and can get touted around the world as being strong support for the AGW hypothesis. The only thing this study supports is the need for better peer review, and at a more basic level, better science education.

Note how the Younger Dryas shows up clearly in the temperature proxies but merely causes CO2 levels to flatten. Thats persuasive that rising temperatures cause rising CO2 levels. When temperatures fell during the YD, CO2 just stopped rising.

Otherwise, climate science is riddled with these kinds of deceptions. If you followed the Larsen iceshelf thread yesterday. I tracked down the source of the ‘2.5C warming over the Antarctic Peninsula’ claim and showed it would have almost no effect on temperatures over 0C and therefore almost no effect on iceshelf melt from atmospheric temperatures. Contrary to the repeated claim it is the cause.

Philip Bradley says:
April 7, 2012 at 11:14 pmNote how the Younger Dryas shows up clearly in the temperature proxies but merely causes CO2 levels to flatten. Thats persuasive that rising temperatures cause rising CO2 levels. When temperatures fell during the YD, CO2 just stopped rising.

This is the point I made in the last thread – the presence of the Younger Dryas makes the initiation of the present interglacial fair game for this kind of AGW trickery, since – as you point out, temperatures rose twice, while CO2 rose only once. The resultant smearing in the time direction of temperature proxies (assisted by the huge variability and error in such proxies) allows Skakun et al. to get away with this conjuring trick. Its enough to allow the MSM e.g. BBC to crow that this powerful skeptical argument – temp rise predating CO2 rise – has been falsified, when it clearly has not.

I leave the readers to consider the fact that for most of the Holocene, eight centuries millennia or so, half a dozen different ice core records say that CO2 levels were rising pretty fast by geological standards … and despite that, the temperatures have been dropping over the last eight centuries …

That discovery deserves to be published. As well, the Sakun paper deserves to be thoroughly and publicly trashed. But I somehow doubt either will occur.

It is quite simple: while temperature changes give clear CO2 changes (about 8 ppmv/°C), the influence of CO2 on temperature is undetectable, even as in the last start of the glaciation CO2 levels remained high while the temperature dropped to a new minimum. The subsequent drop of 40 ppmv had no discernable influence on temperature or ice sheet buildup. See:http://www.ferdinand-engelbeen.be/klimaat/eemian.html

Thus the climate models overestimate the influence of CO2 on temperature to a large extent.

Phillip Bradley says:
When temperatures fell during the YD, CO2 just stopped rising.
====================================================
and phlogiston says:
It is curious how CO2 flatlined during the Younger Dryas.
====================================================

… there should be GCR/Solar activity proxies for the same period which can indicate what else
was happening.

I can see the sun waking up, or the GCR count dropping—or both—BEFORE the big melt started. The clouds roll back and the ice begins to melt. Then the CO2 starts to rise as the oceans warm …

Brilliant and I agree with those calling for this to be written up and published (if they will publish it). And I heard the media run with this as new proof. Simple clear science trashes the sophistry of data manipulation anyday. Occum wins again. I wondered why the CO2 line was truncated. Bravo Sir Bravo.

“showing the difficulty of establishing whether CO2 leads or lags the warming.” Really?

My understanding is that (i) ages ago somebody (Antarctic ice cores?) calculated the cross-correlation function (CCF) between temperature and carbon dioxide so that this difficulty, which is visual not computational, is avoided
(ii) the CCF showed a best fit with CO2 lagging about 800 years behind temperature.
However I have not seen the working or worked it myself out for ice cores.

The CCF is a function of time, and is something like CCF(t)= integral_from_-∞_to+∞_of ( T(τ)C(t-τ)) dτ where T(t) and C(t) are the temperature anomaly and carbon dioxide anomaly at time t, and where great care is taken to get the signs right and the interpretation correct.
If T and C were perfectly correlated (e.g. identical functions displaced by a time X) the CCF would be zero everywhere except for a big spike at either time t=X (or -X: take care of the sign!) If there were no correlation the CCF would be a featureless noisy wobble. If there were no random factors, the CCF would be closely related to the impulse response connecting T and C (or vice versa). With random factors, the CCF would be this impulse response plus some random errors. It may be clear if the CCF is overall higher for t>0 than for t<0, and hence (with due regard to sign) whether T leads C or vice versa.

The CCF is a standard engineering procedure for finding impulse responses buried in noise and is computable in a few seconds, especially, using Fast Fourier Transforms and a programming langange, but is a bit fiddly with Excel!

Poor guys, they probably worked more than a year on that article and it takes Willis a few days to rip it to tiny pieces. And poor as that the scientific standards have fallen to such a low level at Harward as well.

THe steep rise in CO2 in the graphs in Shakun et al seems to have beginning and end inflection points at about 17500 years and 11000 years, whereas in Willis’ graphs they are at 15500 and 9000. I was wonderiing how Shakun et al got a global temperature curve rising from about 17000 years bp to about 13500 bp, and then again from 12800 bp to 10000 bp, when the cloud of proxy dots does not coincide. Apart from any differences about interpretation of data, is there a straight-forward difference in plotted positions of datapoints?

The correct way is to submit a comment to Nature.
If the editor considers it reasonable (so, you must write it reasonably and there must be a scientist on the author list), it will be passed to peer review.

You might post the reviewers comments here as they are anonymous (yet one can always guess as in the Gleick case).

“Exclusive: British polar research in crisis
The scientific body whose groundbreaking discoveries include the hole in the ozone layer is facing massive cuts as the Government’s austerity measures reach new frontiers”

“showing the difficulty of establishing whether CO2 leads or lags the warming.” Really?

My understanding is that (i) ages ago somebody (Antarctic ice cores?) calculated the cross-correlation function (CCF) between temperature and carbon dioxide so that this difficulty, which is visual not computational, is avoided
(ii) the CCF showed a best fit with CO2 lagging about 800 years behind temperature.
However I have not seen the working or worked it myself out for ice cores.

Thanks, Suffolkboy. You are correct. The question was studied in the ice core data, where both the CO2 and the ∂18O can be measured in the same bubbles. At that point you have a chance of determining the lag/lead of CO2 and ∂18O (a temperature proxy).

What Shakun et al. are claiming is that you can use pollen and Mg/Ca ratios and other proxies to overthrow the earlier studies that you reference. I think they cannot do that using their 80 proxies. The data is all over the map.

Is that right – the chart shows the global temperature change from deepest ice age 15,000 years ago to today’s more pleasant levels is only around 2.5 degrees C?

Just about every other reference suggests it was around 6 degrees C, or am I not reading the chart correctly?.

Thanks, Peter. I fear it’s choice B, not reading the chart correctly. The data is all standardized for intercomparison, so the units (as it says) are standard deviations.

In fact, the median warming among all of the 80 proxies is about 4 degrees. The warming for each individual proxy is given in Figs 4-8 in my previous post in this series, “Dr. Munchausen Explains Science By Proxy“.

Willis,
Nick has a pretty good point. Regardless of what has happened outside the period of their study, does the study show something that refutes an earlier understanding? For example, one might show temperature data describing a medieval warming period without any data before or after and with that alone challenge the characterization of our current warmth as “unprecedented.”

“How to lie with statistics” by Darrell Huff – the book deemed a must read for those entering advertising and marketing courses in the 70/80’s – like 1984, take it as primer or warning according to one’s own moral compass.

It was that background knowledge which first alerted me to the junk science – the very first example I was given was a graph giving temperature rise from a norm still in the Little Ice Age – and when I questioned the use of this point as the beginning was fobbed off with the Hockey Stick wipe-out of previous history..

Thanks, Suffolkboy. You are correct. The question was studied in the ice core data, where both the CO2 and the ∂18O can be measured in the same bubbles. At that point you have a chance of determining the lag/lead of CO2 and ∂18O (a temperature proxy).

What Shakun et al. are claiming is that you can use pollen and Mg/Ca ratios and other proxies to overthrow the earlier studies that you reference. I think they cannot do that using their 80 proxies. The data is all over the map.

Thanks Willis, I’ve only been dipping in and out so may have missed that elsewhere, but I hadn’t realised that the CO2 lags data was far far superior to what I can only describe as utter carp … in other words: “run of the mills stuff for warmists”.

There is a point at which denying the sceptics valid and well supported position stops being “a matter of view” and starts becoming blatant fraud. Now that I understand the difference in quality of these two results and see the non-science being written based on all this hot air … I think they have crossed that line.

THe steep rise in CO2 in the graphs in Shakun et al seems to have beginning and end inflection points at about 17500 years and 11000 years, whereas in Willis’ graphs they are at 15500 and 9000. I was wonderiing how Shakun et al got a global temperature curve rising from about 17000 years bp to about 13500 bp, and then again from 12800 bp to 10000 bp, when the cloud of proxy dots does not coincide. Apart from any differences about interpretation of data, is there a straight-forward difference in plotted positions of datapoints?

Good question, Keith. Their graphs are in years before present (1950). My graphs are in BC / AD, so the offset is about two thousand years.

Shakun’s PhD thesis is here (3.7 MB pdf file). None of the figures in his thesis extend to times more recent than -6500 years ago.

Shakun’s Figure 4.2 is the money figure. This is from Figure 4.2 Legend: “(c) Atmospheric CO2 from the Dome C ice core (Monnin et al., 2001) on the Lemieux-Dudon et al. (2010) age model, which is the most recent and likely most accurate chronology. (d) Global mean temperature anomalies with 1σ errors due to chronological and proxy calibration uncertainties estimated from 1000 Monte Carlo simulations.” Later Figures showing CO2 trends refer back to Figure 4.2.

The Dome C ice core data shown in the Monnin, et al, (2001) Science 291, 112-114 (abstract page here, Figure only goes back to -9000 years before the present. Here’s the Monnin 2001 data archived at NCDC. The latest date is -9067 years BP. So, one wonders from where Shakun got the extra 2500 years of CO2 data shown in his Figures.

It turns out he must have gotten it here, which is another NCDC EPICA Dome C ice core data set that provides the Holocene (0-11KYrBP) Atmospheric CO2 all the way up to 435 years BP. It’s from Flückiger et al. 2002 “High-resolution Holocene N2O ice core record and its relationship with CH4 and CO2” Global Biogeochem. Cycles, 16(1), 1010, doi:10.1029/2001GB001417.

Between 10977 and 9899 years BP, the Monnin and Flückiger data sets overlap point-by-point, so they record the same data. And the Flückiger et al., 2002 data set reproduces Willis’ CO2 plot exactly. CO2 begins a steady rise at 6500 years BP, just where Shakun’s T:CO2 plot ends.

So, at the very least, Shakun used ~2500 years of the Flückiger data set without acknowledging it. And having that data set, he must have known about the rise in CO2 after -6500 years BP. And then truncated the CO2 record there, along with the temperature record.

In the text prior to his thesis Figure 4.2, Shakun wrote about the temperatures, “Temperature uncertainties (1 sigma) were taken to be 1.7C for TEX86 (Kim et al., 2008), 1.5 C for pollen and bioassemblages, 10% for ice cores (Jouzel et al., 2003), and are based on quoted calibration errors for Mg/Ca (Anand et al., 2003) and alkenones (Müller et al., 1998). We assumed temperature errors are random through time and among records, which is a maximally conservative approach as errors are likely autocorrelated..”

For those who don’t remember, random errors decrease by 1/sqrtN, where “N” is the number of records. This explains why the Shakun proxy temperature errors in his thesis Figure 4.2 are only (+/-)0.25 C, while the per-proxy errors are about (+/-)1.5 C. They’ve been averaged away as random uncorrelated error.

I assessed Jouzel’s Greenland ice core record. It displays less point scatter than any of his other published data sets, and displays at least two simultaneous error modes. This implies the error is systematic. The standard deviation of that error is 1-sigma=(+/-)0.5 C. As a systematic error, it does not decrease as 1/sqrtN.

Anand, et al., 2003, report a Ca/Mg temperature accuracy limit of (+/-)1.3 C. That’s accuracy, not precision. Accuracy limits do not decrease as 1/sqrtN. They propagate as sqrt[(sum of errors)^2].

Shakun’s Nature Figures 2&3 show proxy temperature uncertainty limits of (+/-)0.1 C over the entire 16,500 years of the record. This (+/-)0.1 C error is smaller than even in Shakun’s thesis, and about 1/10th of the limit of experimental accuracy in the the dO-18 and Ca/Mg temperatures.

The Figures live or die on that low level of T uncertainty. Increase it to a much more realistic 1-sigma=(+/-)1C and T overlaps CO2 across the full record. The entire lead-lag, T:CO2 relationship is lost.

So, Willis has again caught a good one. We have million dollar claims resting on truncated data sets and neglected error bars. Once again a triumph of climate-science and a bell-weather of Nature’s competence.

Willis,
Nick has a pretty good point. Regardless of what has happened outside the period of their study, does the study show something that refutes an earlier understanding?

They claim to show something that refutes an earlier understanding, just as the title says.

For example, one might show temperature data describing a medieval warming period without any data before or after and with that alone challenge the characterization of our current warmth as “unprecedented.”

Here’s what I observe.

1. The proxy data for all 80 proxies is given in their spreadsheet. It runs up as late in some cases as the 20th century.

2. The ice core data for the CO2 shown in their graphs is not given in their spreadsheet.

3. Despite the stated focus of the study on the glacial/interglacial transition, their CO2 data runs for 5,000 years beyond the end of that transition.

4. However, as soon as the CO2 data starts to diverge from the temperature data, it is cut off.

You are welcome to believe that this is just a cosmic coincidence, that it just shows that the gods have a sense of humor.

Here’s the problem, j. If they show the full CO2 record, then they have to explain why the CO2 did all the things they claim it did during the transition, but then changed its ways after they cut off the record.

Look at Figure 2. For eight thousand years, CO2 has been rising fairly rapidly, and the global temperature has been falling. If they show that, their whole argument is threatened.

Now it is possible they just happened to cut the CO2 record off at that time, and it wasn’t related to the fact that showing it would torpedo their argument, and it just happened to be cut at the very time when the CO2 headed upwards … but my money’s betting the other way.

I think the key to examining the validity of their result is to look at the Younger-Dryas event. This instantly stuck me on looking at what they presented where it was occurring at a very different point in time to the Vostok record. Since they were not calling into doubt the timescale of Vostok this implies that they thought Y-D happened over 1000y later in Antarctica. So improbably that they do not suggest it overtly.

Now, seeing your digitisation of their reconstruction on top of the proxy data the deception becomes even clearer. They seem to be using processing with such a heavy damping (or there is so little resolution in the data themselves) that they have completely removed the dip in the Y-D event. This was a huge global event and the obvious key to resolving the key issue they purport to be examining.

The CO2 seems to have risen before the exit from Y-D because the data if failing to resolve it.

‎”consider the fact that for most of the Holocene, eight centuries millennia or so, half a dozen different ice core records say that CO2 levels were rising pretty fast by geological standards … and despite that, the temperatures have been dropping over the last eight millennia …”

The opposite effect in the real atmosphere that CO2 is alleged to have in theory. Is that another aspect of the CAGW hypothesis crumbling that we hear? Yup.

If this doesn’t gain traction I won’t beat it to death, but over at https://wattsupwiththat.com/2012/04/05/more-glacial-junk-science-journalism/#comment-948766 I have been calculating the absorption of CO2 by meltwater from ice sheets for KR and Daveo. If the atmospheric CO2 level has been approximately stable for the past 8000 years and the temperature has been dropping, then there may have been a continuous increase in the amount of ice volume (a difficult number to find).

When the sea evaporates and the precipitation freezes, CO2 is expelled into the air. As the oceans cool on a large scale they pick up more CO2 so there might an approximate balance between the CO2 expelled by new ice and the drawdown of the extra CO2 by the (cooling) oceans. This would give a constant CO2 level in a cooling world if ice volume continued to increase. It seems your plot shows that possibility.

A counter argument could be made that ice and snow ‘cover water’ and could prevent some uptake, but my HP calculator says that ice-sourced CO2 dominates. Yes I am aware that the annual variation has been attributed to land plants but the growth is inadequate and the (larger) CO2-ice argument is not addressed.

Your plot of temp and CO2 supports the idea that accumulating ice expells CO2 into the atmosphere, trumping absorption by cooling oceans. If the Antarctic ice cap is growing, the global rise of CO2 may well match the expulsion. The calculation is simple in round numbers because the air and oceans are both about 300-400 ppm.

If instead the ice sheets are melting, that meltwater will absorb huge quantities of CO2 (relative to human emissions) and the atmospheric level would decrease, just as it does in the NH each summer.

Willis, thanks for the clarification on timescales. This still begs the question how did Shakun et al calculate their global temperature curve? It doesnt look like an average of the temperature data points. Did they weight the ice core isotopic data? Something pulls their line to the right particularly between 17500 bp and 13500 bp. The data cloud says their temperature curve should start to rise around 19000 bp rather than 17500. It looks like it should also go to a higher temperature around 13000 – 14000 bp. THese 2 effects would put their temperature curve to the left of the CO2 curve at least in the time period 19000 – 13000 bp

“Look at Figure 2. For eight thousand years, CO2 has been rising fairly rapidly, and the global temperature has been falling.”

Average it so we can see that..

It is going to take more science on your part then what you offer. The simple fact that over the last ten thousand years CO2 has risen a little over 15ppm speaks for itself. Also the fact the Northern and Southern Hemispheres comes into to temperature alignment at the time of the mild CO2 rise and temperature decrease also makes for an interesting study. (http://i39.tinypic.com/f0qkcw.jpg)

It has been my understanding that there is a difference in timing, to responses of climate change drivers, between the southern oceans and the northern oceans. Would this timing difference show and what would it be, if Willis replotted the proxies for both southern and northern oceans together with the proxy temperature record/s?

Ignore my previous question since you answered it in the preceding reply. Is there anything we can guess on the source of their CO2 data based on their other research or from the article. Shakun et al. make strong assertions while basing it on fuzzy proxies for temperature and without providing the source of their CO2 data. They make an end of discussion assertion with pretty sketchy data – how fuzzy is that?

Yeah, some of the AGW crowd also claim that farming since about 10,000 BC has increased c02 in the atmosphere, delaying the onset of the next ice age.

They claim that the Holocene has been warmer than it should have been (even though the temperature has been dropping), and also longer than it should have been, due to farming and clearing. But to my mind these claims are not supported by the facts.

1. The Holocene has been cooler than previous interglacials. With the human c02 effect, it should have been warmer.
2. The length of the current interglacial is not unusual (we should be slipping slowly into an ice age over the next few thousand years or so).

The paper clearly shows (Because they average the proxy records) that CO2 leads temperature change then drops below it http://i39.tinypic.com/f0qkcw.jpg.. Showing that CO2 should rise again to match temperatures, which it does as shown in your graph. But because you don’t average the proxy temperature records you cant see that..

Great catch Willis!! I had an inclination there was something in there…And for some reason, I can’t get a famous phrase out of my head when I come to Fig 2: “Can you tell what it is yet?” (Rolf Harris) :-)

There is also the uncertainty associated with the age determination – which would be (in my view) a more likely place for confirmation bias to creep in. It is difficult on paired analyses to be sure – but correlation of proxy to proxy is probably a bit of a judgement call.

For example – one could anchor all of the proxies at the point of greatest change with the assumption that the change was global and instaneous – and then see how / if the CO2 in anchored samples preceeded the temperature change.

Great work Willis.
I wonder if the Shakun 2012 CO2 source data did have values for the period between 5000 BC and the present? As you say it is not included in their spreadsheet. If so then it’s hard to imagine any legitimate argument to justify omitting that period. Other than the bleeding obvious of course.
Sounding more and more like yet another team effort?

Classic piece of research checking to ask the question ‘what was left out and why ‘ , its one of those idea that should be taught to any undergraduate. Its failure to occur in this paper peer review is a further reminder that the ‘best ‘ of the science in this area is not even off a standard acceptable for undergraduates essay in any decent university.

That is partly why its so funny to be told that you have to ‘trust’ the science , given the standards in this area are normal so poor , we should anyone actual trust it when its little better than the academic version of ‘what my mate in the pub said’ ?

“The correct way is to submit a comment to Nature.
If the editor considers it reasonable (so, you must write it reasonably and there must be a scientist on the author list), it will be passed to peer review.”

Agree, a Comment published by Nature would correct Shakun’s cherry-picking. But since Nature is now motivated by politics over science, I would not expect any such Comment to see the light of day. Like Mann, Shakun is telling them what they want to hear.

Posted on April 7, 2012 by Willis Eschenbach
I showed there was no way that the proxies could support the title of the paper. Figure 1 recaps that result, showing the difficulty of establishing whether CO2 leads or lags the warming.

Figure 2 shows the surprise …

Figure 2. As in Figure 1. Black circles show Shakun2012 CO2. Additional colored dots show the ice core CO2 records which have data from 26,000 BC to the present.

Dang, I didn’t expect that rise in CO2 that started about 6,000 BC. I do love climate science, it always surprises me … but the big surprise was not what the ice core records showed. It was what the Shakun2012 authors didn’t show.

Each ONE ice core record is unique, Vostok or Bond et al. The truth of describing nature is not to be greater, if individual records are cooked in statistics lump everything together.

If one has the idea that a gas creates heat of saw tooth oscillations ~8° Cel. on Earth over million of years, he may show it by physics. If one has an idea what creates heat of saw tooth like oscillations ~8° Cel. on Earth over million of years, he may show it by physics. A comparison of both is a specious argument and not at all bad science; it is not science.

It is possible to study the unique global records (plural), and you can find phase correlations in the (few) spectra. Each increase of global temperature proxy is powered by a heat source and each saw tooth like frequency has its very own geometry of the heat oscillator.

It is well known here that as well high frequency global temperature oscillations as measured by UAH but also very low frequency global temperature oscillations as recorded in Vostok or by Bond et.al. 2001 have agreements with specific solar tide functions in phase and frequency. The latter can be shown in four graphs because of the big time interval:

It is one thing to fight against stupidity in the CO2 war, but it leads the scope away from the question what physical processes vary the heat source by which geometries.

An alternative may to verify each anonymous green dot in the graph for correctness. Seems to be a funny job if there are only bad News from xyzgate soaps.

Science is to show agreements in nature, not to being skeptic on possible agreements, because skeptic is not a method of science.

“These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.”

They are explaining a specific event, and presented graphs that showed that period.

I did a similar analysis of the ice core data with similar results. I observed the proxie temperature deviation beginning around 4000 BC. For a likely explanation of why, see http://www.kidswincom.net/climate.pdf.

Like I said earlier: That Shakun-paper should be withdrawn. This piece clearly shows why.
I hate it when scientists leave the inconvenient parts out. That’s misleading and again it shows “pal-review” at its best.
I definitely never going to subscribe to Nature whatsoever.

To Willis Eschenbach: Are you going to try to convince Nature to withdraw the Shakun-paper?

Willis,
Nick has a pretty good point. Regardless of what has happened outside the period of their study, does the study show something that refutes an earlier understanding? For example, one might show temperature data describing a medieval warming period without any data before or after and with that alone challenge the characterization of our current warmth as “unprecedented.”

You would have a point if the paper wasn’t trying to turn over such an important theme – that temperature lagged CO2 rise at the end of the last glaciation and therefore CO2 caused the temperature increase. Assuming Shakun et al had the extra CO2 data it shows that CO2 can rise without any temperature increases (a direct contradiction to their central argument) and that CO2 has been rising for 8,000 years, not just since man started burning fossil fuels (a direct contradiction to the heart of AGW).

Nice work Willis. You should publish this. You should also show single graphs of temperature versus year for Greenland and the Antarctic because they clearly show the Antarctic warming up almost 2,000 years before Greenland (there is no way the NH caused the SH to release CO2 to warm the SH).

Someone suggested averaging the time series but if you look at the individual proxies some of them don’t look real and others are neither correlated to Greenland or to Antarctica – so what would you expect from this averaging process?

I think WUWT may be under attack. If I scroll down several screens, I get redirected to a blank WUWT page and can’t get back. This is happening only for WUWT for me, which is why I think it’s directed specifically at you. I’m using IE 9.0.5. (Firefox 10.0.2 is OK for now.)

Has Willis’ observation that CO2 proxies have generally shown an increase in CO2 beginning 6000BC while temperature proxies have generally shown a decrease in temperature since 8000BC been made before? If so, why isn’t this one of the top 5 arguments to cast doubt on the CAGW hypothesis?

Stokes argument that it was quite right to leave out the later CO2 records because the investigators were focusing on a relatively narrow time period is specious. The writers were using data to hypothesize a mechanism to explain events at a particular time. If that same data extended casts doubt on that hypothesis, a scientist must include that data and explain how the hypothesis is still valid.

Of course Willis explained yesterday why the temperature proxies cannot be averaged – hence the hypothesis is not based on anything scientific to begin with.

Back to my main point – why has the gross relationship of the temp and CO2 proxies over the last 10,000 years not been a prominent argument (that laypeople can understand) casting doubt on the warmers?

Thank you WIllis, excellent postings that resulted in the deconstruction of the paper.
Shakun’s explanation itself was already smelling bad: ice melted first, but that was not global warming, no changes in albedo through ice melting but changes in ocean currents. So North Hemisphere melts ice but it is only South Hemisphere warming which releases CO2 which then creates global warming.

>> Not at all. Their argument, at least as stated in the abstract, is:

“These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.”

>> They are explaining a specific event, and presented graphs that showed that period.

When papers start using phrases like “support the conclusion that …” they are saying they have not proved anything, simply that there is not blatant contradiction with what they are saying. ie yet more unsubstantiated hypothesis. Why these kind of non results are considered worthy of begin published is more to do with politics than science.

Anyone can publish “results” about unproven ideas not being disproved because they and have not tried hard enough and have chosen to ignore half the data that would have disproved them.

If they were then to explain why their “anti-phase” plus in-phase combo becomes “anti-phase” plus “anti-phase” in the last 5000 years we may have something to talk about.

As it is, this is just more IPCC fodder and cargo cult science. Your rather ridiculous attempts to claim it means anything just shows how blinkered you are yourself.

Most of the time period covered here is like the previous nearly 400,000
years, where few warmists heavily dispute CO2 lagging temperature. During
that time, the total of atmospheric, hydrospheric and biospheric carbon was
constant, and atmospheric CO2 content was one of the positive feedbacks.

But once humans started transfering carbon from the lithosphere to the
atmosphere, increase of CO2 became a cause of warming. It appears to me
that the debate should be over how much or how little, rather than whether it
does or does not.

I have done research of my own, leading me to findings of modern global
climate sensitivity ranging from .67 to 1.5 degree C/K per factor-of-2 change
of CO2, and decreasing as global temperature and greenhouse gas
presence increase. This is much less than figures advocated by most
advocates of existence of manmade global warming via CO2.

But before I got that far, I handled debate as to whether CO2 was higher
during WWII than now, whether nature has recently been adding or removing
CO2, and cherrypicked 10, 11, etc. year parts of global temperature record
beginning with a century class El Nino and ending with a La Nina. When the
debate I handled was along those lines, I thought that manmade CO2 causing
global warming meant causing *as much* warming as advocated by most
advocates of manmade CO2-caused global warming.

The Greenland Ice sheet temperature data and record of CO2 supports your finding and posting. CO2 rises throughout the 6000 year period while temperatures drift down. The ice sheet data also shows the Dansgaard/Oeschger cycles (also referred to as Bond Cycles) which are cycles of warming and cooling. Obviously CO2 does not cause Dansgaard/Oeschger cycles of warming and cooling. Bond noted in his published research that the cycles have a 1500 year period and that there are concurrent cosmogenic isotope changes that occur at the same time as the warming and cooling.

The 20th century warming appears to be a Dansgaard/Oeschger cycle as it correlates with a large solar magnetic cycle change.

http://climate4you.com/
Fig.3. The upper panel shows the air temperature at the summit of the Greenland Ice Sheet, reconstructed by Alley (2000) from GISP2 ice core data. The time scale shows years before modern time, which is shown at the right hand side of the diagram. The rapid temperature rise to the left indicate the final part of the even more pronounced temperature increase following the last ice age. The temperature scale at the right hand side of the upper panel suggests a very approximate comparison with the global average temperature (see comment below). The GISP2 record ends around 1855, and the red dotted line indicate the approximate temperature increase since then. The small reddish bar in the lower right indicate the extension of the longest global temperature record (since 1850), based on meteorological observations (HadCRUT3). The lower panel shows the past atmospheric CO2 content, as found from the EPICA Dome C Ice Core in the Antarctic (Monnin et al. 2004). The Dome C atmospheric CO2 record ends in the year 1777.

The past temperature changes show little (if any) relation to the past atmospheric CO2 content as shown in the lower panel of figure 3. Initially, until around 7000 yr before now, temperatures generally increase, even though the amount of atmospheric CO2 decreases. For the last 7000 years the temperature generally has been decreasing, even though the CO2 record now display an increasing trend. Neither is any of the marked 950-1000 year periodic temperature peaks associated with a corresponding CO2 increase. The general concentration of CO2 is low, wherefore the theoretical temperature response to changes in CO2 should be more pronounced than at higher concentrations, as the CO2 forcing on temperature is decreasing logarithmic with concentration. Nevertheless, no net effect of CO2 on temperature can be identified from the above diagram, and it is therefore obvious that significant climatic changes can occur without being controlled by atmospheric CO2. Other phenomena than atmospheric CO2 must have had the main control on global temperature for the last 11,000 years.

Willis: I’d add my voice to getting someone on board with you, perhaps Dr. Spencer or someone like that, and condense this down and send it to Nature. The odds are that Nature will not accept it, but the act of getting it polished and condensed for submission will improve it and make it more powerful.

Willis, all your postings are excellent and the last two are no exceptions. This last one I doooo like as it does not leave much room, if any, for the idea that a doubling of CO2 can, will or does contribute to “maybe” 1 °C of atmospheric warming (biased little me).

Looks like you may be one of those “heretics” who are giving skeptics like Fred Singer a bad name, however it may just be true that a wise person waits until all the “available evidence” has been analysed before he (or she) apportions blame.

It appears to me that the debate should be over how much or how little, rather than whether it does or does not.

Anthony would agree. So would Lindzen. Monckton, too, for that matter. The real debate centers around feedbacks.

One will note that the actual instrumental record is being called into considerable question. it is possible that 20th warming, itself, is exaggerated (perhaps by a factor of two).

I handled debate as to whether CO2 was higher during WWII than now,

It once seemed to me that it must have been higher. Industry was going full guns (“Spare Gas fur Rusting”) and a hundred major cities were incinerated or blasted to bits. But OTOH a lot of the oil and coalfields were in the combat zone, and a lot of the labor force was at the front. Proxy records show a slight CO2 drop during the height of the war as compared with 1940. After all, I’m not sure i know what to think.

When you average out all the Northern Hemisphere Proxy’s and compare them to the Southern Hemisphere Proxy’s as shown in this graph http://i44.tinypic.com/34gncox.jpg you can see why some of the proxy’s have a late warming start. These proxy’s are not cherry picked, it is just the simple fact that the Hemisphere’s warmed at different times and the proxy’s show that. Here is a graph of all the proxy sites used to get a global temperature average http://i41.tinypic.com/1432dtw.jpg

“Climate sensitivity is not constrained by the last two decades of imperfect satellite data, but rather the paleoclimate record.”

NASA climatologist Gavin Schmidt

Well Willis, you have estimates of [CO2] and ‘global’ temperature estimates. A plot of Ln([CO2]) vs Temperature will give you a slope, with error-bars in two dimensions, that will give you the ‘climate sensitivity’.

Of course, on will find that CO2 is not directly coupled to temperature, and the directionality of temperature change give two estimates of ‘climate sensitivity’.

Congratulations to WUWT/Willis Eschenbach for providing the raw material for *TWO* articles!

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Part I: WUWT/Eschenbach verify
the deglaciation CO2/temperature relations of Shakun2012

In a reanalysis of the data used by Shakun et al. in their “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” (Nature, 2012), WUWT/Eisenbach have affirmed the main conclusion of Shakun et al:

Temperature is correlated with and generally lags CO2 during the last (that is, the most recent) deglaciation. … These observations support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Part II: WUWT/Eschenbach verify
the CO2/temperature “Hockey Stick” of Mann1999

Extending the data used by Shakun et al. in their “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” (Nature, 2012) to encompass the anthropocene era 5000BP–present, WUWT/Eisenbach have affirmed the main features of the CO2/temperature “Hockey Stick” of Mann et al: in “Global-scale temperature patterns and climate forcing over the past six centuries” (Nature, 1999):

Greenhouse gases emerge as the dominant forcing during the twentieth century. Northern Hemisphere mean annual temperatures for three of the past eight years are warmer than any other year since (at least) AD 1400.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

But Willis, to see this clearly, your data plots have to include *all* the temperature proxies, and *all* the CO2 data, for the *complete* period 5000BP–present. Because if you’re going to criticize Shakun et al. for not showing all their data, and for truncating their time series arbitrarily, aren’t you thereby obligated to show all of *YOUR* data?

To phrase this same point positively, Willis … you’ve already done a terrific service to both the skeptical and the scientific communities, by verifying the good analysis that Shakun et a: made of CO2/temperature relations during the last deglaciation (22000BP–6000BP), during which time the “main event” was the melting of the glaciers. Now you have a fine opportunity to repeat that analysis for the period (600BP–present), during which time the “main event” is the “hockey stick” of CO2/temperature.

This analysis, affirming both the mutual forcing of CO2 and temperature, and the reality of the 20th-21st century “Hockey Stick” in both quantities, would go far toward building a bridge of mutual appreciation and trust between skeptics and scientists— from which our entire planet would benefit.

So go for it, WUWT/Willis! Assure us that forcing is real, and so is Mann’s Hockey Stick!

Nice work Willis, but can I suggest (even on Easter Sunday) that if you do send this as a comment to Nature that you use BP (i.e. calibrated years pre-1950) rather than BC, and you explicitly note which of the calibration data sets this is based on (i.e. was it IntCal04 or IntCal09?), and how this influences results. IntCal09 tends to give somewhat older pre-Holocene ages than IntCal04.

Something tells me the Holocene CO2 concentration increase has been successfully dealt with in other papers. If nothing else, there’s ongoing change of Earth orbital parameters and the change in CO2 concentrations was several orders of magnitude slower than the change we’re usually discussing now, it can’t be told how exactly would it look like if the CO2 concentration didn’t increase over the Holocene. Maybe we’d be deep in another ice age already without it? I can’t really tell, but this is what I found discussing the matter:

“And I leave everyone to ponder how far climate “science” has fallen, that a tricksy study of this nature can be published in Nature, and can get touted around the world as being strong support for the AGW hypothesis. The only thing this study supports is the need for better peer review, and at a more basic level, better science education.”

Since Rio+20 is coming up soon, I’m expecting a lot more of these types of peer reviewed reports in the coming months. I wouldn’t be surprised to see some of their now discredited wild claims come back to life in new reports and papers.

a) The CO_2 “rise” it shows starting at 20 Kya is utterly spurious. CO_2 was utterly flat (to falling a little) from 25 Kya to 15 Kya. I don’t need to compute for that data to see that no fit is resolvable from a zero-trend straight line.

b) As always, the Younger Dryas has much to tell us. If CO_2 is responsible for the warming trend in a positive feedback cycle, then it should have pulled the temperatures up across the YD instead of following the temperature curve down. Although as noted it looks like the YD signal is very attenuated in much of the coastal tropical data and is prominent only in the Antarctic cores. The CO_2 looks like it follows the tropical (much subdued) signal.

c) The Holocene Optimum was an easy 0.5 K warmer than today. Since then, the mean temperature has steadily dropped, while CO_2 has increased with a clear crossover. Conclusion: CO_2 variation isn’t a highly sensitive driver, or the main driver, of global temperatures. Secondary conclusion: Something else is!

While I am happy to believe that the bistable oscillations observed over the last half million or more years are coupled to astronomical cycles, that does not suffice to explain the bistability. There is a causal factor missing. I don’t think it is closing off of circulation patterns in the ocean because the effect isn’t sufficiently discrete for that (on the 5 million year scale). The temperature doesn’t plunge down, it very steadily drops. This is a knob being turned, not a door being slammed shut. Furthermore it is a knob that has been turned before, back when today’s continents were a distant event in the future. It’s not inconceivable that ice ages are caused by continental drift but the data makes it somewhat implausible.

It would be very, very interesting to look at Mars or Europa or any other planet with an accessible thermal history to see if there is evidence of Martian heating and cooling on the billion year timescale that matches that of the Earth’s. That would be direct evidence that the Sun itself is very long period variable in some way that might explain it. Perhaps it is connected with times that the solar system drifts through interstellar dust clouds and the sun is slowly “fed” with infalling matter, and when it drifts out the sun returns to a slightly cooler steady state.

says:
April 8, 2012 at 7:17 am
In re …
wmconnolley says:
April 8, 2012 at 12:48 am
*******
There have been two quite juvenile responses to wmconnelley’s link and its contents.

Pedro~ We are speaking of a person who has distorted the biographies of many skeptic scientists, to smear their reputations and their efforts in climate science.

We are speaking of a person who has made changes to over 5000 climate articles, to bolster support of his religion, ie, AGW.

We are speaking of a person who had either blocked or banned several hundred people from wikipidea, either because they were trying to post scientific pieces that ran counter to his faith, or because they were trying to correct egregious errors he wrote into their pieces.

Perhaps a more mature comparison and analysis of his views with those of Willis would be useful … particularly to those of us who are not scientifically-inclined.

All wmconnolley did was link to a page that opens with this,

It is indeed a very fundamental question about whether the CO2 leads or lags the temperature. If there was somewhere in the ice core record where CO2 increases and temperature does not, then our understanding of the greenhouse effect must be faulty. However, so far we don’t find such a place.

Now go look at Figure 2 above and the question is answered. CO2 has increased for the last 6,000 years and temperatures have not. Ergo, their understanding of the greenhouse effect is faulty.

Its just the usual obsfurcation from warmists like wmconnolley. Post a link and rely on the fact 95% of people won’t follow it or understand it. Real Climate does this all the time.

Nick Stokes wrote:
“Their title is “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” Seems clear to me. And that’s what they plotted.”

That’s really what they plotted? Then why didn’t they stop plotting the graphs at 10K BP, which would be the beginning of the Holocene? Their graphs all end at <7K BP which goes beyond the last deglaciation.

Re: Pete
From the very first paragraph of the link pointed to by wmconnelly

It is indeed a very fundamental question about whether the CO2 leads or lags the temperature. If there was somewhere in the ice core record where CO2 increases and temperature does not, then our understanding of the greenhouse effect must be faulty. However, so far we don’t find such a place.

I believe Willis’s figure 2 shows just such a place where CO2 increases without a temperature rise.

As a dynamicist, I was intrigued by the ‘high frequency’ transient in some of the proxy data that has a positive peak around -12k yrs and a negative peak around -10k years. I would love to see someone correlate that with other events during that era.

The rise is about 10 ppm in that last period which would lead to 0.1 C of temperature increase, so it might be hard to see. The modern era was truncated off the right side of this graph, but it would currently be about 3 on that scale moving to somewhere near 10 by 2100, just to put it in perspective, so are we concerned about that little ramp of 10 ppm?

Pete says:
April 8, 2012 at 7:17 am
There have been two quite juvenile responses to wmconnelley’s link and its contents.
=============================
“Thus there is no surprise in the idea that the end of the ice age was kicked off by something other than CO2. however once it started, CO2 appears to be involved in keeping it going.”

When you average out all the Northern Hemisphere Proxy’s and compare them to the Southern Hemisphere Proxy’s as shown in this graph http://i44.tinypic.com/34gncox.jpg you can see why some of the proxy’s have a late warming start. These proxy’s are not cherry picked, it is just the simple fact that the Hemisphere’s warmed at different times and the proxy’s show that. Here is a graph of all the proxy sites used to get a global temperature average http://i41.tinypic.com/1432dtw.jpg

There are cycles of warming followed by cooling and occasionally abrupt cooling that has a period of 1470 years +/- 500 years. The 8200 year BP abrupt cooling event, the Younger Dryas 12,900 BP year cooling event, 4200 year BP cooling event and so on follow this cycle. The Greenland ice sheet data show that atmospheric CO2 isn’t the driver of the Bond cycles and in fact does not change in response to the planetary temperature change.

Bond cycles, ≈1,470 ± 500 years, recorded in the Greenland ice sheet data.

Bond events are North Atlantic climate fluctuations occurring every ≈1,470 ± 500 years throughout the Holocene. Eight such events have been identified, primarily from fluctuations in ice-rafted debris. Bond events may be the interglacial relatives of the glacial Dansgaard–Oeschger events, with a magnitude of perhaps 15–20% of the glacial-interglacial temperature change.

Gerard C. Bond of the Lamont-Doherty Earth Observatory at Columbia University, was the lead author of the paper published in 1997 that postulated the theory of 1,470-year climate cycles in the Holocene, mainly based on petrologic tracers of drift ice in the North Atlantic.[1][2]
The existence of climatic changes, possibly on a quasi-1,500 year cycle, is well established for the last glacial period from ice cores. Less well established is the continuation of these cycles into the holocene. Bond et al. (1997) argue for a cyclicity close to 1470 ± 500 years in the North Atlantic region, and that their results imply a variation in Holocene climate in this region. In their view, many if not most of the Dansgaard–Oeschger events of the last ice age, conform to a 1,500-year pattern, as do some climate events of later eras, like the Little Ice Age, the 8.2 kiloyear event, and the start of the Younger Dryas.

– The Holocene was punctuated by irregular 1500±500 year cooling events which have correlatives in the North Atlantic (deMenocal et al., 2000; Bond et al., 1997).
– When compared to the Holocene sequence at Site 658C, the results suggest we are overdue for an abrupt transition to cooler climates, however orbital configurations These results are consistent with other high-resolution records of the Last Interglacial from the North Atlantic and support the view large-scale climatic reorganizations can be achieved within centuries.

I tend to agree with Nick on his point that during the period under consideration, leading and lagging assumptions are questionable regarding the oft repeated notion that CO2 lags behind temperature increases. However, the authors over-state their case saying that CO2 leads temperature.

My big critism would be that they should have ended both data sets at the same point, leaving the recent past to someone else’s endeavors. Nick, you would have to agree with me on this point at least.

“…I leave everyone to ponder how far climate “science” has fallen…”
In the end, they will have carried the flag in support of bankrupting the world and this country. And in that end will themselves meet their own end.

The most ridiculous and irritating consequence is in the meantime all that money could be going to science that would have a positive impact on our lives rather than to the villainizing of CO2 crap you so properly reveal.

Manfred (April 8, 2012 at 5:35 am) linked to Piers Corbyn’s note on statistical paradox:http://www.weatheraction.com/docs/WANews12No20.pdf
—-
Phillip Bratby (April 7, 2012 at 11:41 pm) responded: “Hi Willis, could you make a plot with different colours for northern/southern hemispheric data to support/reject Corbyn’s analysis ?”
—
Careful as follows if/when you do this Willis:
The current distribution of continents is NOT symmetric about the equator.
Earth’s asymmetric.
The equator is NOT the fulcrum for all key variables.
The sharpest gradients are over the Southern Ocean.
Here’s a visual reminder based on recent decades:
_ Isotachs & Pressure at 550K:http://i56.tinypic.com/14t0kns.png_

Wandering off in conspiracy land again I see. You need to read Eric Wolff.

How about trying to understand the issues and making your own arguments. It seems to me that Wolff’s criticism doesn’t apply here. Here’s what Willis said in a previous comment:

Thanks, Suffolkboy. You are correct. The question was studied in the ice core data, where both the CO2 and the ∂18O can be measured in the same bubbles. At that point you have a chance of determining the lag/lead of CO2 and ∂18O (a temperature proxy).

wmconnolley, intellectual laziness such as what you just demonstrated is what turned me into a skeptic. There was a guest post on boingboing in which the author attacked the hockey stick because there was plenty of historical evidence that the MWP happened. The best the permanent editors could do was point to an article somewhere else and assert that the hockey stick was valid. In that very moment the skeptic in me was born.

What you are doing, by pointing to Wolff, is confessing that you don’t understand the issues. You could at least try, otherwise we will all think you are just a garden variety troll.

Having had first hand experience with a challenge of extremely poor science being published in Nature, I suggest Willis give them a very brief chance to retract the Shakun 2012 paper. Give them the above information and suggest immediate publication of your analysis of the paper in question or the retraction of the offensive paper.

In my case (Nature rejected our rebuttal stating it was too long if you can believe it) it wasn’t until the original paper was deconstructed by several groups and other journals published papers (including ours) demonstrating the serious flaws that eventually Nature did disavow the original paper.

I further suggest a landslide of comments to Nature from anyone who values real science, and see if (but probably when) Nature will reject your rebuttal of the Shakun 2012 paper,

I strongly suggest Willis seek publication in another journal and then wait for the further disgrace of the original peer review at Nature to be aired.

Once again Real Science takes another shot and its credibility suffers at the hand of the AGW team. Pity

Lincoln Sparrow, you seem capable of elucidating us on scientific method. So I will point out that 1) the words in the conclusion you quote includes oceanic circulation affects but this was not a part of the study, and that 2) you seem willing to speak of the word used by the authors -“generally”- as a statistical finding. The paper does not appear to support this word as a statistical finding (generally statistical findings are included in the section called “Results”). Might this word have been used by the authors when error bars and tests of statistical significance did not show promising results?

Willis I admire your admirable tenacity in pursuing this matter and further checking a paper which is trying to support the cornerstone of CAGW, that rising CO2 precedes warming, and showing it to be wrong.

There is a fundamental problem with those scientists involved in climate science who believe in CAGW. They seem unable to consider anything which does not agree with what they believe and have been told to believe.

Some scientists deliberately or inadvertantly manipulate their papers accepting only ‘data’ which agrees with the hypothesis they want others to accept as a theory.

For other scientists their errors are clearly an inability to allow any alternative view to change their understanding of reality. Unless these scientists are able to consider alternative views they will not be able to accept that they might be wrong. It takes great character and determination to oppose peer pressure and begin to address ideas that run contrary to personal beliefs and in this way start to make “the intuitive leap” needed to create new ideas. Those scientists who are able to open their minds to new ideas are inevitably the ones who make new discoveries.

WUWT is the informal forum for review of papers on climate science, which because of its openess and scrupulous analysis has, for me, become far more important and reliable than journals like Nature. The decline of rigorous peer review may partly explain why statistics comparing WUWT with Nature.com show that readers of WUWT spend about twice as much time on site than do readers of Nature.

They cherry picked a date at the end of the ice age, when CO2 levels were at their lowest, and had no place to go but up…either that or die….CO2 levels increasing can be explained biologically, because it was limiting…..and did exactly what it should do at the time…..the second the weather gave it a break, the process started….irregardless of the weather after that

You can’t pick an extreme like this and try to compare it to not extreme…and get anything meaningful out of it

“Solubility of Helium – He – in Water”
Helium seems to walk to the beat of a different drummer. Really hot, really cold and in between; it does unexpected things. I did not realize that it had this step change happening between 20-40 C in water. Weird. I wonder if anyone ever correctly predicted anything helium does. I wonder what effect its non-liner actions have on things around it.
Learned something again today. Thanks.

If we take the Shakun2012 conclusion seriously, that Northern Hemisphere temperature lags CO2 concentration by about seven centuries, then we conclude that the temperature record *should* show “Hockey Stick” increases in quantities like global surface temperature, ocean temperature, and sea-level … portending global temperature rises of many degrees C and sea-level rises of tens of meters.

Thanks therefore are due to WUWT/Willis Eschenbach, for vividly and clearly, with every detail set forth, showing the entire skeptical community precisely how it comes about that the paleoclimate data support, plainly and simply, all of James Hansen’s main climate-change predictions.
>>>>>>>>>>>>>>>>>>

Summary: The paleoclimate analyses of WUWT/Willis Eschenbach and James Hansen are rapidly converging toward a consensus that AGW is real, serious, and destined to accelerate in coming decades.

“Dang, I didn’t expect that rise in CO2 that started about 6,000 BC. I do love climate science, it always surprises me … but the big surprise was not what the ice core records showed. It was what the Shakun2012 authors didn’t show.

I’m sure you can see just what those bad-boy scientists have done. Look how they have cut the modern end of the ice core CO2 record short, right at the time when CO2 started to rise again …”

This is meaningless nitpicking to cover up the fact that your previous criticisms didn’t stick. Shakun2012 did not set out to explain the evolution of temperature and CO2 during the holocene period. They were interested in the period of deglaciation.

The rise over 7900 years, until the onset of the industrial age was about 20ppM or 8% This is very small compared to the 100ppM or 45% rise that the authors were looking at during the period of deglaciation. As a forcing, an 8% change in CO2 is minscule, and other forcings such as orbital and axial forcing could be at work here.

Your comment has no bearing on the validity of the paper you are trying so hard to impugn.

The rise in CO2 over the last 6000 years could be associated with deforestation due to man. So, I don’t think that rise is any kind of a smoking gun. Of course, that also allows for some of the modern warming to be assicated with deforestation rather than emissions.

Once again the complexity of this subject is way above the level where we can make any reasonable assessments given the data we have. There could have been so many other factors involved which makes this entire field of study pretty much a SWAG.

I seem to be missing something. Shakun et. al imply that the ice core data is local. Don’t the O18 levels in the ice cores represent GLOBAL levels of O18? If not, just why should O18 levels be a local phenomenon?

I assume I must be wrong about O18 being global since averaging a bunch of local proxies in an attempt to overturn a global proxy would be nonsensical. Would someone please give me the ‘elevator speech’ explanation why O18 isn’t global?

Willis, thanks for the clarification on timescales. This still begs the question how did Shakun et al calculate their global temperature curve? It doesnt look like an average of the temperature data points. Did they weight the ice core isotopic data? Something pulls their line to the right particularly between 17500 bp and 13500 bp. The data cloud says their temperature curve should start to rise around 19000 bp rather than 17500. It looks like it should also go to a higher temperature around 13000 – 14000 bp. THese 2 effects would put their temperature curve to the left of the CO2 curve at least in the time period 19000 – 13000 bp

Per the paper:

The data were projected onto a 5°x5° grid, linearly interpolated to 100-yr resolution and combined as area-weighted averages.

I have several problems with that procedure, which I may write about later.

Excellent deconstruction. Do we know what CO2 source data they used and how that matches up against the NOAA source data?

From the paper:

The atmospheric CO2 record from the EPICA Dome C ice core12, which has recently been placed on a more
accurate timescale13, has a similar two-step structure and is strongly correlated with the temperature stack (r2=0.94 (coefficient of determination),
P=0.03; Fig. 2a).

It is shown as the black circles above in Figs. 1 and 2. It fits well with the NOAA source data.

It has been my understanding that there is a difference in timing, to responses of climate change drivers, between the southern oceans and the northern oceans. Would this timing difference show and what would it be, if Willis replotted the proxies for both southern and northern oceans together with the proxy temperature record/s?

I addressed this question in a comment to my previous post, “Dr. Munchausen Explains Science By Proxy”, here’s the graphic from that comment.

“These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.”

They are explaining a specific event, and presented graphs that showed that period.

Nope. The “specific event” is the temperature change at the end of the ice age.Their graphs showed well beyond the period of the temperature rise at the end of the last ice age. In fact, the temperature rise was about 6,000 years long. They showed another 5,000 years past that, almost as long as the rise itself, and about half the length of the entire Holocene. So your argument, that they just showed what they were discussing, runs aground on an ugly reef of fact … they showed half the Holocene on their graph.

Finally, their claim is that the warming is “driven by increasing CO2 concentrations”. But the CO2 continues to increase, and the warming stops … which threatens their argument, as I said above.

You can continue to believe they extended the record for 5,000 years beyond the interglacial transition and that it was just an unlucky coincidence that they happened to stop showing the CO2 at the very instant it started to rise.

Me, I’ve dealt with too many victims of Noble Cause Corruption to believe in coincidences that unlikely.

“The only thing this study supports is the need for better peer review, and at a more basic level, better science education.”

More red tape isn’t the answer for a system already red taped into a straight jacket. Rigid strength’s good for support, but flexibility’s essential for mobility. The problem is a lack of people qualified to supervise. Messing around with peer review’s patently NOT a substitute for NO ONE getting fundamentals right. Iterative adjustment of math education at a sustainable pace (it will take decades if not millennia) is the viable liberating option.

All this is handwaving unless you write a letter of Comment to Nature and they withdraw the paper

I could write fifty comments to Nature. They will never withdraw the paper, and at least somewhat reasonably so. Journals generally only withdraw a paper if it can be shown to be actual fraud, not just incorrect claims.

In addition, I would argue strongly that what is written here has more impact than a “Comments Arising” in Nature.

But Willis, to see this clearly, your data plots have to include *all* the temperature proxies, and *all* the CO2 data, for the *complete* period 5000BP–present. Because if you’re going to criticize Shakun et al. for not showing all their data, and for truncating their time series arbitrarily, aren’t you thereby obligated to show all of *YOUR* data?

Say what? As far as I know I did show all of the CO2 data and all the proxy data for the entire period 26,000 BC to the present … what am I missing?

Pamela Gray says:
April 8, 2012 at 8:59 am
“I tend to agree with Nick on his point that during the period under consideration, leading and lagging assumptions are questionable regarding the oft repeated notion that CO2 lags behind temperature increases.”

Okay, so what is the value of Shakun’s paper? I’m amazed that Nick Stokes and Pamela Gray, two whom I’ve come to respect here, would not be troubled by the the rest of the record. Shakun is attempting to show that the present day theory of CO2 rise causing temperature rise is also true of the end of the last ice age. This is the context in which you must understand the paper. Let us pretend that we didn’t know about the greenhouse effect of CO2 and Shakun was exploring this possibility. Let us assume that he was able to satisfy us that CO2 “slightly” (his words) preceeded temp in the record up to 6000 ybp. Surely looking at the rest of the data since 6000bp, Shakun would be disappointed that the relation didn’t appear to bear up. If this is okay for you guys and Dr. Shakun, then it would seem possible to present square orbits and P1V1=P2/V2 with constant T up to 6000ybp. Please, tell me you are troubled by the truncation of the data which appears to hide the real basic question being investigated by Shakun.

Well that didn’t take long did it? Shakun junk science completely debunked by Willis!

Even the usual trolls sound ridiculous in the defence of their cherished beliefs. For best hilarity, see Nick Stokes previous posts. Apparantly Shakun shows that CO2 rises preceded temperature rises. Ehrm, no they didn’t Nick. Taken individually, Willis has shown that the temperature proxies are all over the place – some follow the CO2 proxy, some precede it and some don’t have any direction when CO2 changes.

If a sceptic had produced such a study to show that CO2 lagged temperature, Stokes would have been all over it. The credibility of this man has just fallen lower than Nixon after Watergate. Shame to see an otherwise worthy opponent fall so low.

Nice work Willis, but can I suggest (even on Easter Sunday) that if you do send this as a comment to Nature that you use BP (i.e. calibrated years pre-1950) rather than BC, …

I used BC and AD here as a deliberate choice, because I am writing for a mixed audience, and many folks are much more used to BC / AD than they are to years before 1950.

… and you explicitly note which of the calibration data sets this is based on (i.e. was it IntCal04 or IntCal09?), and how this influences results. IntCal09 tends to give somewhat older pre-Holocene ages than IntCal04.

I used the timescale used by the original authors for each study. The Shakun2012 paper also includes (in some cases) alternative time calculations, either IntCal04 or 09. However, none of them change the results in any significant manner, as the differences in the timings of the proxy warmings are thousands and thousands of years, much more than the slight adjustments from different timelines.

Volker Doorman: Science is to show agreements in nature, not to being skeptic on possible agreements, because skeptic is not a method of science.

This is backwards. Science is unique among the ways of knowing in its great respect for skepticism. Other approaches emphasize faith, but scientists accept as possible truths only those assertions that survive extensive skeptical challenges.

2. Proof that Man has been disturbing the atmosphere for 6,000 years. Or something has.

3. Intriguing: Younger Dryas shows up as sudden jump of CO2 about 12,000 YBP, ending about 10,300 YPB? With a DROP in temperature of about 1C, by eyeball of the green dots? Proof that higher CO2 causes temperatures to fall, by the cherry-picking method.

Actually, the Younger Dryas interval is an interesting part of their work.

4. And the research ASSISTANTS didn’t notice the more recent data has been left out?

There are going to be some interesting war stories from the younger set in a few years time.

Willis Eschenbach says:
April 8, 2012 at 10:31 am
Dave says:
April 8, 2012 at 3:34 am
“It has been my understanding that there is a difference in timing, to responses of climate change drivers, between the southern oceans and the northern oceans. Would this timing difference show and what would it be, if Willis replotted the proxies for both southern and northern oceans together with the proxy temperature record/s?”

I addressed this question in a comment to my previous post, “Dr. Munchausen Explains Science By Proxy”, here’s the graphic from that comment.

The unanswered question is: What power in Watts have and where are the terestrial climate change drivers?

If they would be on Earth, why then the terrestrial temperatures follow heliocentric (tide) functions?

Willis, this is really good work, and I want to repeat my recommendation that you submit a letter to Nature.

About this of yours: I could write fifty comments to Nature. They will never withdraw the paper, and at least somewhat reasonably so. Journals generally only withdraw a paper if it can be shown to be actual fraud, not just incorrect claims.

In addition, I would argue strongly that what is written here has more impact than a “Comments Arising” in Nature.

Respectfully (I hope you believe this), I want to repeat my recommendation that you submit a letter to Nature. One way or another they will have to respond, and if they merely ignore you, you will be able to inform us of that fact, which some day could be another episode to be listed in the growing doubts that Nature is honest and rigorous in its treatment of climate science. It will add to the impact of your posts here, not be less or more, as you put it. Also, there are examples of papers being withdrawn for incorrect claims, not just for fraud. The Shakun paper was OK, except for one unsubstantiated claim that got blown out of proportion: the claim that they had shown that CO2 increase preceded global temperature increase. You showed before that their claim had no empirical support, once the full data were presented in a way to assess random variability. You showed today that any mechanistic interpretation of the unsubstantiated claim is contradicted when the full CO2 record is included with their temperature proxies. Shakun et al probably only included the truncated CO2 record because of their interest in the end of the particular ice age (or may claim so), so there is no need to assert any dishonesty, merely an unfortunate focus by them.

You have already done most of the work that a letter requires. Just put it all together, include all graphs that you have produced up til now, and keep the text succinct, omitting any hints of accusations. I don’t know about Nature, but Science will occasionally publish two really short notes together alerting readers to a critique and rejoinder that they can read about on line.

I bet that there was disagreement among the authors over the insertion of the unsubstantiated claims. I know of instances of that happening, especially in the transition of a PhD thesis to a submitted paper. In the academic world, publish or perish is the norm, and a young researcher may be forced to go along with claims he or she does not agree with. Mind you, I don’t know that happened in this case, but if you write your letter without any hint of exposing possible dishonesty, …, well, I think you have a better chance of a better outcome.

Chris V (April 8, 2012 at 7:29 am) wrote:
Am I missing something here? The graphs from Shakun’s paper that are included with the abstract all show CO2 levels up to the present.
Willis Eschenbach responded (April 8, 2012 at 10:55 am):
Say what? I find no graphs in Shakun’s paper that shows anything more recent than about 6,500 years before the present. Which graphs are you talking about?

My question: The graphs in the actual Shakun’s paper – behind paywall – apparently are different from the ones that Chris V refers to (coupled to the Abstract). Willis, can you please clarify this point because it is vital for your analysis!

Willis, this is good work. many thanks. You wrote: Finally, their claim is that the warming is “driven by increasing CO2 concentrations”. But the CO2 continues to increase, and the warming stops … which threatens their argument, as I said above.

I agree, and that is why I think you should submit this as a letter to Nature. You have made two good points: (a) claims that CO2 increase preceded temperature change are not supported in the data that they reported on in their paper; (b) claims that CO2 increased caused temperature increase are undermined by the complete CO2 records. You have already done most of the work for your letter. The letter will add to, the impact of these posts, not simply be less than or more than. If they don’t publish, you will alert all of us to that decision. In your letter, include all the graphs that have presented to us so far, but keep the text succinct and avoid hints of dishonesty. Mistakes like this can occur in many ways, too numerous to mention. This field has too many accusations of dishonesty already. In this case, it was probably a result of focusing too narrowly on one transition in the geological record. I would say that it is more important for the science that you get the full record published (your figure 2 today), than to ascertain how the mistake (as I call it) occurred.

Next, the 6500 cal year BP limit is covered in the readme tab of the exel sheet:“All ages are given in yr BP, where Present = 1950 AD. Age models were constructed with focus on the deglacial interval (22-6.5 ka). They should be used with caution outside of this time window (e.g., ages near core tops were not constrained to be greater than 0 yr BP).”

Furtermore, all temperature reproduction work is proxies. Inherently an unavoidable affirming the consequent fallacy. (If A then B, B hence A). An example of a catastrofical crash can be seen within this work!
There are several ways to reconstruct sea surface temperatures, the most reliable is thought to be TEX86 (googleable) and C37 alkenone. Huguet et al 2006 (in the study) tried both with disastrous results:http://www.agu.org/pubs/crossref/2006/2005PA001215.shtml
These are in the study, tabs NIOP-905, while the graphs should be identical, this is the plot:

There is no reason to assume that other proxies are any better, including the isotopes in the ice cores. But this is the kind of evidence that should support the notion about temperature resonstructions.

Beyond killing this paper, it also kills the whole AGW hypothesis – 8000 yrs of generally increasing CO2 & associated general decline in temps. 180 deg out of phase with the hpothesis – how much more data do we need anyway?? Come on now! Put a fork in AGW! It’s done!

“Your comment has no bearing on the validity of the paper you are trying so hard to impugn.”

As his ^comment^ makes clear, Eric Adler has zero understanding of the scientific method. It is the duty of scientific skeptics to tear down conjectures whenever they can. Willis has done an excellent job of deconstructing Shakun et al.

Shakun is just pulling a Michael Mann trick, using carefully cherry-picked proxies to arrive at a conclusion at odds with the mountain of evidence showing that a rising temperature results in rising CO2, just like a warming Coke outgases CO2.

Mr. Eschenbach’s rebuttal of the Shakun paper is a disgrace to science. The new scientific method is to look only at data that supports your theory. Other data is irrelevant. I’m sure he knows this but mischievously follows the older outdated and antiquated scientific method. <—– humor

The unanswered question is: What power in Watts have and where are the terestrial climate change drivers?
If they would be on Earth, why then the terrestrial temperatures follow heliocentric (tide) functions?

“Finally, their claim is that the warming is “driven by increasing CO2 concentrations”. But the CO2 continues to increase, and the warming stops … which threatens their argument, as I said above.”

You may believe that this threatens their argument, but the increase in CO2 was only about 8%. If the climate sensitivity were 3C, as most climate scientists believe, and CO2 were the only driver, the change in temperature at equilibrium would be about 0.3C. This is 1/10 of the average global temperature change during the period studied in Shakun2012. Accounting for this era would be the subject of another paper, and would be much more challenging given the many small forcings that need to be taken into account, and the fragmentary data.
The change in orbital forcing are in the opposite direction and are probably responsible for driving a good part of the decrease in temperature.

Am I missing something here? The graphs from Shakun’s paper that are included with the abstract all show CO2 levels up to the present.

Willis Eschenbach responded (April 8, 2012 at 10:55 am):
Say what? I find no graphs in Shakun’s paper that shows anything more recent than about 6,500 years before the present. Which graphs are you talking about?

My question: The graphs in the actual Shakun’s paper – behind paywall – apparently are different from the ones that Chris V refers to (coupled to the Abstract). Willis, can you please clarify this point because it is vital for your analysis!

No, they’re the same graphs. It’s hard to see in the abstract. But if you click on one of the graphs and then zoom in on it (in Safari it’s command – “+” on the Mac, dunno what key combo zooms in on the PC) you can see that in all cases the furthest right number on the years scale is “8”, for eight thousand years before present (1950). Then there’s one tick mark and about half a unit to the end of the graph.

All of the graphs, in other words, end at about 6,500 years before the present (BP).

This is a prime example of why the internet should not be subject to political control or to control by the UN or any other international agency. The internet, among other things, provides the opportunity for scientific review and promotes discussion where there would otherwise be none.

[blockquote]Lincoln Sparrow says:
April 8, 2012 at 9:36 am
Summary: The paleoclimate analyses of WUWT/Willis Eschenbach and James Hansen are rapidly converging toward a consensus that AGW is real, serious, and destined to accelerate in coming decades.

Kudos therefore go to WUWT, Willis Eschenbach, and James Hansen![/blockquote]

Appears “A.Physicist” is being channeled ….

[Note: “Lincoln Sparrow” is the same poster as “R Kcin” and “Marcella Twixt”. ~dbs, mod.]

Many people here misunderstand Hide the decline.
The issue had to do with more than not showing data. It had to do with actually removing data from archives.

Let’s use another example: In Fall et al Anthony and company looked at 1979 to present.
When Berkeley released a preprint that looked at 1950 to present, many people jumped all over that decision. maybe for good reason. maybe not.

The authors here set out to make a case about a particular time period. They are not hiding any data or removing it from archives ( as in hide the decline) The extra data is out there for somebody who wants to make a different case about different time periods.

The bottomline is that nothing you can find in proxies will ever be strong enough evidence to reverse known physics. GHGs increase and, all other things being equal, temperature will increase.
When you find periods where the two ( GHGs and temp) do not move in concert, you know one thing: all other things were not equal. You don’t know and you can’t know that GHGs dont increase warming. You dont and cant because fundamental physics is correct. We known that its correct because we building working devices based on that physics.

“Your comment has no bearing on the validity of the paper you are trying so hard to impugn.”

As his ^comment^ makes clear, Eric Adler has zero understanding of the scientific method. It is the duty of scientific skeptics to tear down conjectures whenever they can. Willis has done an excellent job of deconstructing Shakun et al.”

It is clear that you have zero capability of dealing with the point that I made, and neither you nor Willis Eschenbach has answered it.

“Shakun is just pulling a Michael Mann trick, using carefully cherry-picked proxies to arrive at a conclusion at odds with the mountain of evidence showing that a rising temperature results in rising CO2, just like a warming Coke outgases CO2.”

Shakun has certainly not cherry picked. He used 80 proxies covering all regions of the globe. Willis has not made that charge because he obviously knows better.

You should cut down on the number your trollish posts and do some real thinking for a change.

Willis, thank you very much for clarifying the question whether the graphs shown with the Abstract are different from the “real” ones in Shakun’s paper. I had zoomed in to some extent and by mistake thought (as Chris V perhaps did as well) that the furthest right number was 0 instead of 8.

So you have convinced me now that Shakun left out all the recent data from 6,500 years before the present. I am still not sure that this was done deliberately, but the authors surely would have done the decent thing by showing ALL the relevant data (and then explain why the CO2-temperature relationship would be different in recent times).

As a dynamicist, I was intrigued by the ‘high frequency’ transient in some of the proxy data that has a positive peak around -12k yrs and a negative peak around -10k years. I would love to see someone correlate that with other events during that era”

The 10Be record from GISP2 ice and from the Taylor dome give the same line-shape. Of course, we all know that solar output, cosmic ray levels and Stella dust can have no impact on temperature or atmospheric CO2.

Willis, will you be invited to ICCC-7 ? I am one of those amature geeks that watches the heartland streaming of the event. I would love to see this as a presentation, and some of your other climate investigations.

Chris V (April 8, 2012 at 7:29 am) wrote:
Am I missing something here? The graphs from Shakun’s paper that are included with the abstract all show CO2 levels up to the present.

My question: The graphs in the actual Shakun’s paper – behind paywall – apparently are different from the ones that Chris V refers to (coupled to the Abstract). Willis, can you please clarify this point because it is vital for your analysis!

No, they’re the same graphs. It’s hard to see in the abstract. But if you click on one of the graphs and then zoom in on it (in Safari it’s command – “+” on the Mac, dunno what key combo zooms in on the PC) you can see that in all cases the furthest right number on the years scale is “8″, for eight thousand years before present (1950). Then there’s one tick mark and about half a unit to the end of the graph.

All of the graphs, in other words, end at about 6,500 years before the present (BP).

w.

The graphics are tiny on the abstract page – and as Willis notes people are not seeing what they actually show. Another member posted this link:

Which shows – by scale at bottom – that the record is truncated at point they stop reporting CO2 appx 6500 years BP.

Willis,
To avoid being accused by alarmists of truncation of data, modern CO2 levels and temperatures might be overlaid. I’m sure someone will do it. To make it real, other CO2 proxies should also be shown.

… The authors here set out to make a case about a particular time period. They are not hiding any data or removing it from archives ( as in hide the decline) The extra data is out there for somebody who wants to make a different case about different time periods.

Good to hear from you. You are correct when you say that the authors are talking about “a particular time period”. My point is that that specific time period was very carefully chosen.

The bottomline is that nothing you can find in proxies will ever be strong enough evidence to reverse known physics. GHGs increase and, all other things being equal, temperature will increase.

Again you are 100% correct that all things being equal temperature will increase. But the climate actively adapts and responds to changes, so things are never equal. If temperatures change, cloud patterns change. Ocean currents change. Tropical cirrus forms earlier. We get more El Ninos. And the balance is maintained. The amazing stability of the planetary temperature is the result of those and dozens of other homeostatic and thermostatic mechanisms.

Look at Figure 1. The median rise shown there is about 4°C from the low point around 16,000 BC to the high point around 8,000 BC. Which means that over the last ten thousand years, the globe has cooled by around a degree. For a heat engine which throws away about 30% of the incoming energy (albedo reflections) that is governed by something as insubstantial as clouds, that is astounding stability.

When you find periods where the two ( GHGs and temp) do not move in concert, you know one thing: all other things were not equal.

Since in natural flow systems all other things are never equal, this statement doesn’t mean anything.

You don’t know and you can’t know that GHGs dont increase warming. You dont and cant because fundamental physics is correct. We known that its correct because we building working devices based on that physics.

I see the problem. You are conflate two separate ideas. They are:

1. GHGs cause increased forcing.

2. Increased forcing causes increased warming.

The first statement is fundamental physics and is undoubtedly true.

The second statement, as you point out, is only true if other things are equal … but other things are never equal. So it is not “fundamental physics” by any stretch of the imagination.

Willis, you may have missed Pat Frank’s comment at April 8, 2012 at 2:38 am. Thought he made some excellent points. My own view is that Shakun’s thesis has a single thrust, which is typical of graduate theses, but NATURE should have a broader view and so their editorial policy should instill some context, but evidently they do not.

Willis, will you be invited to ICCC-7 ? I am one of those amature geeks that watches the heartland streaming of the event. I would love to see this as a presentation, and some of your other climate investigations.

I was hoping so, but I guess my invitation must have gotten lost in the mail … I spoke at a previous conference, the 4th one. I livetooned it here and here. There was a video of my presentation somewhere on the web, I can’t find it now.

Willis: “…I leave everyone to ponder how far climate “science” has fallen, that a tricksy study of this nature can be published in Nature … The only thing this study supports is the need for better peer review …” You are absolutely right. I sometimes wonder about that too when I see these tricksy studies. Nature is not the only one, though, Science is into it too. Trenberth and Fasullo published an article in Science tracing earth’s energy and mysteriously lost track of it. Everything was fine until 2004 when the energy began to leak away and by 2008 eighty percent of it was missing without a trace. They wondered about its whereabouts and asked: “If the extra energy has gone into the ocean, where has it gone?” Well, the ocean seemed to be unlikely on the face of it because they had just stated that “Since 2004, ~3000 Argo floats have provided regular temperature soundings of the upper 2000 m of the ocean, giving new confidence in the ocean heat content assessment.” Now what do you know, new equipment comes on line and energy makes a disappearing act! I don’t think this paper was ever reviewed because if it were the first thing any referee would have done is to send him back checking those buoys. The lesson is that rank has its privileges: if you are a big shot in the climate field the least you can expect is to have your paper waved past the editorial process.

The standard line is that CO2 effects were too small pre-WWII to have a significant effect on temperature, and being skeptical that marginal changes in CO2 are responsible for much temperature change post-WWII, I have no trouble accepting that, but Willis is right: for those who take the opposite view, the increasing levels of CO2 over the Holocene ought to cause warming.

Googling Law Dome CO2 images to verify Willis’ numbers, guess who pops up with the first 10,000 year image? John Cook:

Every time I see a Temp/CO2 record like this it seems there is one big obvious question: “What caused temps and CO2 to stop their rapid rise and plateau appx 8000-9000 years ago?

It would seem that is the direct signature of the climate “thermostat” mechanism. Temps had been rising rapidly along with CO2 and then they abruptly stopped, and remained relatively stable with minor cooling trend since.

I found some info on the “8200 year event” – here is a note regarding some possibilities:

“The 8200-year event is widely regarded as the strongest Holocene cooling episode, with clear expressions in Greenland (1, 2), the North Atlantic (3), Europe (4-11), North America (12-14), North Africa (15), and the Venezuelan Cariaco Basin (16). Decreased snow accumulation rates, lower levels of atmospheric methane, and increased atmospheric dust and sea-salt loadings indicate widespread dry conditions (17, 18). Explanations usually involve a perturbation of the North Atlantic thermohaline circulation (THC) by increased freshwater inputs asso- ciated with the decay of the Laurentide ice sheet (6, 19). A high-resolution global circulation model (GCM) indicates that a freshwater pulse of a magnitude similar to that associated with the catastrophic drainage of the large proglacial lakes Agassiz and Ojibway could have produced the 8200-year event, including a very brief warming episode within the event (20).”

Whatever triggered the response was strong enough to cause a dramatic shift – from rapid rising temps and CO2 to the long, stable temp period we’ve seen since.

These graphs of the very stable temp record over the last 8000+ years – which show the recent warming the AGW side bases all their doom and gloom, sky is falling meme on – show that the recent warming is not even outside the normal variation of the last 8000+ years of stable temps.

That is what made me a sceptic. If the warming they are scare mongering about, when looked at in even a 8000-9000 year period does not even break thru the natural variability of that time period (let alone when reviewed in climate cycle time frames) then how can it be of ANY import or concern.

If one glacial to interglacial climate cycle is one climate “day” (lasting appx 115,000 years) that would make the last 8500 years equal to appx 1 3/4 hours of that one climate cycle “day” – less than 8%. How can a temp change that is within the historical natural variability range of a time period comprising less than 8% of a single typical climate cycle have any statistical relevance regarding climate change at all?

[Note: “Lincoln Sparrow” is the same poster as “R Kcin” and “Marcella Twixt”. ~dbs, mod.]

A serious question: does WUWT make a deliberate practice of selectively “leaking” posts thought to be anonymous? If so (as the above evidence indicates), then what selection criteria is WUWT presently using in making the determination to “leak” or not? And do WUWT’s readers have the right to know the WUWT’s “leak” criteria?

[Reply: Sockpuppetry violates site Policy. For example, you also post as “Frederick Davies”. ~dbs, mod.]

Peer review in climate science journals has once again been shown as a flawed and ‘tricksy’ process. Some of these science journals make themselves less relevant the more they publish. In contrast Anthony and contributors on WUWT have enabled instant ‘peer review’ by both unbiased and biased scientists (and a mixed audience).

It is also useful to read posts from people with ‘questionable’ views as it enables insight into their mindset, occasionally they even forward a good argument and it is not good to surround yourself with ‘yes men’ (journals take note). I am sure I’m not the only one who finds it helpful when contributors reveal relevant verifiable history about some of these people. I also find the moderators do a good job of removing nasty malicious or over the top comments (even mine).

Most of my contributions tend to be of a satirical nature, hopefully on themes and people who deserve it and if I infrequently raise a smile that is a success. Sometimes it’s good to ‘bring it down a notch’ and call on ‘Flash Gordon’ when alarmists say we only have hours to save the Earth.

“Climate sensitivity is not constrained by the last two decades of imperfect satellite data, but rather the paleoclimate record.”
NASA climatologist Gavin Schmidt

Richard Alley’s position denies Gavin’s position starting at 23:00
Alley fights to tell staff members at Penn State that scientists’ “Global Warming” is not based on the so called “broken hockey sticks”, but on the satellite record.

One thing that Willis’ analysis shows is that ice core CO2 data are very poor as a proxie for global temperature as compared to the O18 index. I suggest that the actual atmospheric CO2 concentrations were considerably higher when we had higher temperatures as indicated by the O18 index. I further suggest that a more accurate estimate of pre-historic CO2 concentrations can be obtained by establishing a modern day global temperature/atmospheric CO2 relationship (not a model fudge factor) and work backwards using O18 as the temperature proxie. In so doing, we should be able to settle the lead/lag debate.

A. Scott says:
April 8, 2012 at 1:50 pm
How can a temp change that is within the historical natural variability range of a time period comprising less than 8% of a single typical climate cycle have any statistical relevance regarding climate change at all?
========================
It doesn’t……………you can’t use your brain to play this game

I leave the readers to consider the fact that for most of the Holocene, eight millennia or so, half a dozen different ice core records say that CO2 levels were rising pretty fast by geological standards … and despite that, the temperatures have been dropping over the last eight millennia …
———–
So what are you trying to say here Willis? That this graph proves that rises in global temperature do not cause CO2 out gassing from the oceans? Which would be proof that that this favorite climate skeptic and climate warmist argument is wrong.

That’s laudably skeptical of you Willis to follow where the data leads irrespective of whether it supports your initial position.

Consider that the ice core CO2 data are a poor proxie of the actual pre-historic atmospheric concentrations of CO2. We don’t really know what happens to the air bubbles under the extreme pressures of the many meters of ice.

If you could ever get over your fixation on “carbon” propaganda, you might conclude that CO2 may not have the effect claimed. And of course there is also the well established CO2 lag time, which allows for divergence.

Hugo M says:
April 8, 2012 at 12:36 pm
Volker Doormann said on April 8, 2012 at 11:24 am:
“The unanswered question is: What power in Watts have and where are the terestrial climate change drivers?
If they would be on Earth, why then the terrestrial temperatures follow heliocentric (tide) functions?”

Volker,
what is the value of Pearson’s r for these two time series?

I don’t know. I have no tool to compute the value, but maybe you can check it out from the data (links in the graph)..
My point was my general questions here to whom it concerns.
The heliocentric climate world view seems to be an anathema by the peer here, well known that the saw tooth like oscillations can easy be calculated out of the sun’s geometry and the photon diffusion time after Prof. R. Ehrlich:

It seems people more fight holding magazines clean than fighting for truth in science.

Certainly one can understand why the number of practicing scientists who post on WUWT is very nearly zero. That number of scientists will now diminish by one.

Comment: It’s sobering to contemplate that anonymizing networks that were conceived to protect the free speech of citizens against state tyranny and retribution, now find service in protecting the free speech of citizens against the too-high prevalence of WUWT-hosted abuse and threats.

REPLY:Oh, please.

First, We have a policy page. I don’t let certain people in my own home that abuse my trust, and my home on the Internet is no different. People that don’t wish to abide by policy get called out on and if they don’t change their behavior, end up getting banned. There have been a few. For example I banned recently a person known as Victor Barney for making hateful racist comments and comments about the intelligence of women. I suppose by your logic, you’d support him taking on a new persona to get around the ban and spew the same hate all over again?

Second, Show us “abuse and threats”. I’d really like to see those myself.

Third, People are welcome to comment on all sides of the issue, however we have limits, based on our experience and made quite clear in the WUWT policy page. For the same reason I don’t allow people in my real home to act boorishly, so it goes on my home on the Internet.

Fourth, Like any private establishment, we reserve the right to refuse service to anyone. If any of our policy bothers you, you know where the door is.

Fifth, WordPress.com our hosting service, expressly supplies the IP adresses of all commenters, not only on our blog, but on every WordPress blog in existence. When we see multiple comments from the same IP address under differ handles, it is easy to identify, we don’t go looking for it.

Sixth, Our success stands on its own. We don’t plan to change policy for a few whiners or people that like to play shape shifting games or people that think shape shifting equates to free speech.

Several people have said that orbital forcings are the reason for the decline in temperature over the holocene. As the earth goes around the sun, over time the eccentricity and the obliquity of the orbit slowly changes.

The problem with this theory is that the orbital forcings change the distribution of the sunlight, but barely change the total sunlight at all. Since there is no change in TOA insolation, why would that cool the earth?

The prevailing hypothesis is that the change in surface temperature is equal to the climate sensitivity times the change in total TOA forcing … and over the period in question there was no change in total forcing from variations in the earth’s orbit.

Nor is it at all clear what effect the change in the distribution of the sunlight would make. Generally the changes meant warmer summers and cooler winters at high latitudes … would that warm or cool the planet?

“Although these all show the hockey stick shape, the differences between them prior to 1850 make me very nervous. If I were on the greenhouse deniers’ side, I would be inclined to focus on the wide range of paleo results and the differences between them as an argument for dismissing them all.”

If the proxies are so over the map, can any of them be trusted to be representation of past temperatures?

When you find periods where the two ( GHGs and temp) do not move in concert, you know one thing: all other things were not equal. You don’t know and you can’t know that GHGs don’t increase warming. You don’t and can’t because fundamental physics is correct. We known that its correct because we building working devices based on that physics.

Man has build functioning devices long before we understood how they worked. We built steam engines even as we subscribed to the phlogiston theory and had a woeful grasp of thermodynamics. We built dynamos, which worked, based on a totally wrong understanding of electricity. (Hence why positive “current” flows the wrong way compared to the actual electrons.)

Some humility about our understanding is useful at all times. And particularly so in new areas, such as climate science. My bet is that almost everything we “know” will be wrong, at least in details.

What would the warmists suggest could be a plausible possible alternative mechanism for pumping all of that extra CO2 into the atmosphere at the end of a glacial period, that continued for thousands of years?

The solubility of Carbon Dioxide in ice is about two orders of magnitude less than the solubility in water. Freeze sea water. What happens to CO2 levels?
If I take a Northern Hemisphere [pick any Northern Hemisphere you like] covered in thick glaciers and melt them rapidly into the oceans, will the atmospheric CO2 concentration go up, or will it go down?

“So you have convinced me now that Shakun left out all the recent data from 6,500 years before the present. I am still not sure that this was done deliberately, but the authors surely would have done the decent thing by showing ALL the relevant data (and then explain why the CO2-temperature relationship would be different in recent times).”

The author chose to study the era that he did, and did ground breaking work in calculating the global temperature change during the end of the last ice age. This enabled him to model regional temperature change and show how CO2 drove climate change.

Shakun’s paper was an excellent achievement and earned him a doctorate. He was under no obligation to study the holocene era as well. There is no real issue of decency here, unless you believe in some kind of conspiracy theory.

As I have pointed out, using the generally accepted figure of 3C for climate sensistivity in that era, if CO2 were the only driver, the temperature increase would have been about 0.3C. In fact variations in the earth’s orbit and axis are currently causing long term cooling. Reduction in summer sunlight in the Northern Hemisphere allows more snow and ice to remain on the ground. The enhanced reflection of the sun’s rays causes cooling. Variations in solar intensity, volcanic aerosals and vegetation also affect the evolution of climate. The presence of so many small forcing factors make modeling the holocene period very complicated.

The increase in CO2, on a percentage basis, due to industrial emissions, is comparable to the 45% seen during the last deglaciation period, but the current duration for this increase is about 200 years, versus the 5000 year period that it took for the last deglaciation. So the current change in CO2 represents a comparable forcing factor to the deglaciation.

One more point about the Younger Dryas. We known the YD both began and ended rapidly, in less than 50 years and perhaps as few as 10. Looking at figure 2, the plateauing of CO2 clearly precedes the YD cool period. Are we to interpret this as, when CO2 stopped rising, the climate rapidly cooled?

Similarly, the resumed rise in CO2 occurs during the cool period.

Or more likely, it indicates a calibration issue, and the CO2 dating is too early (or the temperatures too late).

“If the proxies are so over the map, can any of them be trusted to be representation of past temperatures?”

Hmm… yes, and no !
yes they can be considered to be a representation of past climes (not just temperatures don’t forget) but the term representation is the crux. Do you remember the old method of drawing a big version of something using a tracing device (can’t think of the name at the minute) or vice versa – well, in my opinion, all proxy data is at one end of one of those devices – the thing is, which end? do the proxies under or over estimate? etc, etc. Why couldn’t they calibrate ice core data to ‘current’ times, for example?

Steven Mosher: The authors here set out to make a case about a particular time period. They are not hiding any data or removing it from archives ( as in hide the decline) The extra data is out there for somebody who wants to make a different case about different time periods.

Shakun et al make a claim that is weakly supportable from their analyses, namely that CO2 increase preceded global temperature increase (their monte carlo test is nice, but not strong, and ignores the antecedence of the Antarctic temp rise[unless I missed it — only one read through so far.]) They made a much less supportable claim, namely that CO2 increase may have caused the global temperature increase; it is less supportable because Antarctic temperature increase preceded CO2 increase, so “global temperature increase” is just as likely to be a consequence of Antarctic temperature increase; and the causal link is further undermined by the data that Willis presented today.

The causal claim was inappropriately trumpeted in the press release, which is one of the reasons for my recommendation that Willis submit a letter to Nature. The paper is good up until it makes a causal claim, but the causal claim should surely be challenged.

Wandering off in conspiracy land again I see. You need to read Eric Wolff.

I read your comment, wm, and came to one conclusion:

You maintain diffusion of CO2 in the forming ice likely causes a biased trend, for which you assign a value of “several hundred years” (which still isn’t enough to reverse the order of T rising before CO2, by the way).

Yet I know of no diffusion process that would produce this so-called “biased” results of which you speak. Diffusion is known to work much the same in all directions; one could argue there’s as much diffusion of CO2 downward through the solidifying snow as there is upwards.

The only caveat you attempt to establish in your link is that there is “uncertainty in the data” (your words).

Therefore what you call “wandering off in conspiracy land” is based on nothing more than “uncertainty”, yet in my opinion it is just one unsubstantiated supposition–if anybody’s pushing a conspiracy, it is you. It is you that’s trying to convince people of biased diffusion that has no little or no basis in fact. It is you that’s trying to fit natural processes to your “religion” of CAGW. And to accuse people of “wandering” yet you admit “uncertainty” is truly beyond the pale. (You must have nightmares at night about pointed refutations of papers like Shakun’s)

And for those of you supporting wm here, you’re guilty by association.

Read his link and see if you can come up with scientific proof refuting his real conspiracy–we’d all be glad to hear what you have to say.

Then come back and delve into the meat that Willis presents and you’ll see a big difference. Nobody, especially wm, should be throwing charges of “wandering” when all they’ve got as “evidence” is “uncertainty”. It does their argument no good.

I agree that the cut-off date in the paper being coincident with the rise in atmospheric CO2 during the Holocene is too clever by half, and for sure not a coincidence, since it clearly weakens the “case” the paper is trying to make. But the rise in CO2 (and atmospheric methane as well) starting about 6500 years ago is something that has been widely recognized (and the cause for which debated) for quite some time. I think the most widely accepted position is a significant contribution to increases in CO2 and methane from the rise of agriculture. The continued cooling during the Holocene, in spite of rising CO2 and methane is (of course) an inconvenient fact that must be explained. I have seen several explanations offered, including increased albedo from farming offsetting the CO2/methane forcing, and shifting of the season of the Earth’s perigee, and no doubt other explanations have been offered. Are they right? Who knows… and who cares?

FWIW, my take is this and all similar studies try to draw far to much information from a noisy jumble of proxies. It is clear that Milankovitch cycles are primarily responsible for ice ages; trying to discern what are (at best) speculative secondary factors is mostly a waste of time. After all, if the IPCC claims no ability to narrow climate sensitivity to better than “2C to 4.5C” using all available instrumental data and decades of intensive study, how much credibility can one reasonably give an analysis of very noisy proxies from 10,000 years ago? IMO, it is just kind of silly drivel… climate porn, if you will. But it is too bad this kind of stuff makes its way into so many breathless reports of “confirmation of sensitivity to CO2” in newspapers all over the world.

The bottomline is that nothing you can find in proxies will ever be strong enough evidence to reverse known physics. GHGs increase and, all other things being equal, temperature will increase.
=======================
We hear “all other things being equal…” a lot. So, please tell us when the last time was that all things were equal?

How about we dipense with the purely hypothetical and start addressing the real world?

Although the article’s limited time application may be all it meant to be, it is used by Nature as much more. Here is part of Nature’s lead editorial, “Bolstering the Link,” which clearly shows Nature intended Shakun to help Gore and the global warming cliques. It is internally contradictory to a comical degree, but I will not comment except I think it should repeated as a thread on WUWT titled like “Fisking the Link” for imputing things to Shakun et al. that they did not say:

“Bolstering the Link”

….
First, as Jeremy Shakun at Harvard University in Cambridge, Massachusetts, and his colleagues show on page 49, carbon dioxide does drive atmospheric warming. Uncontroversial stuff, perhaps, yet the link continues to be questioned by people who would play down the risks of human greenhouse-gas emissions. The queries re-emerged in 2006, when former US vice-president Al Gore showed a graph of historical carbon dioxide levels and temperature in his movie, An Inconvenient Truth, and was accused of glossing over the relationship between the two. So let there be no confusion now: the new study confirms that, as Earth emerged from the last ice age some 19,000 to 10,000 years ago, rising global temperatures were preceded by increased global carbon dioxide in the atmosphere — a result that emphasizes the role of carbon dioxide in driving global change in the present day. This relationship is a foundation stone of climate science and of policies to regulate greenhouse-gas emissions, and it is solid.

Quelle surprise! the climate sceptics may shout — scientists find proxy data and use a computer model to get the answer they wanted, to seal the conspiracy. Then let the second paper this week show that modern science does anything but offer self-serving results to support existing ideas. For, in a paper published online, Ben Booth and his colleagues at the Met Office Hadley Centre in Exeter, UK, use a different model to question conventional wisdom on how the climate of the North Atlantic Ocean operates (B. B. B. Booth et al. Nature http://dx.doi.org/10.1038/nature10946; 2012).

This study looks at the impact of aerosols — such as sulphur dioxide particles ejected by volcanoes and linked to the burning of coal — on sea surface temperatures there. Aerosols that reflect sunlight and can promote brighter cloud formation have been known for some time to affect climate, but the idea has gained appeal in the media during the past decade, under the tag ‘global dimming’.

The study suggests that global dimming could underlie warm and cool periods observed in the North Atlantic basin in the twentieth century — a variability known as the Atlantic Multidecadal Oscillation (AMO). And because the AMO has been implicated in global processes, such as the frequency of Atlantic hurricanes and drought in the Sahel region of Africa in the 1980s, the findings greatly extend the possible reach of human activity on global climate. Moreover, if correct, the study effectively does away with the AMO as it is currently posited, in that the multidecadal oscillation is neither truly oscillatory nor multidecadal.

The implications of this are great, both for study of the climate system and for the impact of policies to control aerosol emissions. It also shows that solid science does not have to be settled science, and that this is no bad thing.

Willis: If you intend to plot CO2 on a serious graph along with temperature, I suggest that you first take the log of the CO2 data (which should be proportional to any temperature change it may cause), then normalize. It may not make any difference, but you don’t want to look like Al Gore in An Inconvenient Truth rising on the lift to point out where the are headed (perhaps 1.5 doublings of CO2) on that infamous graph of temperature and CO2 vs time.

The IPCC projections are based on an unacceptable 3ºC+ per 2xCO2, but those projections are falsified by the planet. So we can disregard the AR-4 hindcast/forecast models due to their failure to come anywhere near real world obsevations. Global temperatures have been flat to declining for 15 years, yet the IPCC still claims a preposterous 3ºC+ sensitivity number:

Note the flat temperatures since the late 1990’s.

Next, the ice core data clearly show that rises in CO2 follow rises in temperature:

This relationship [rises in CO2 always following rises in temperature — has remained constant for the past 400 millennia:

Shakun et al. have given the alarmist contingent a fatally flawed paper that attempted to overturn decades of data. Their paper was hand-waved through pal review, which ignored the fact that most of the inconvenient Holocene was omitted; only the small cherry-picked part that supported their conjecture was used.

However, the fact that Willis easily deconstructed Shakun’s flawed methodology means nothing to the tribalist alarmist crowd, which as usual completely ignores the scientific method — just as they ignore the central fact that a warming ocean outgases CO2, not vice-versa. CO2 is not warming the oceans; warming oceans are outgasing CO2. But try to explain that simple fact to the true believer alarmist crowd.

“However, the fact that Willis easily deconstructed Shakun’s flawed methodology means nothing to the tribalist alarmist crowd, which as usual completely ignores the scientific method — just as they ignore the central fact that a warming ocean outgases CO2, not vice-versa. CO2 is not warming the oceans; warming oceans are outgasing CO2.”

I don’t want to steal Willis post, but I would like to show and tell.
Here are the plots of EPICA Dome C, Deuterium temperature, -log(Dust mass), Iron and Sulphate mass, and the Taylor Dome 10Be measurements (Taylor has the best 10Be dataset).

[…] So the current change in CO2 represents a comparable forcing factor to the deglaciation.

Maybe we should work on tripling the CO2 contribution to the atmosphere, then, so the temperatures will actually go UP instead of declining.

That, or your hypothesis is incorrect.”

Your ignorance of climate science is showing. You seem to be referring to the recent slowdown in global warming. It is well understood that internal variation during such a period can overcome the global warming trend due the GHG’s. In addition sulfate aerosals, which have a short lifetime in the atmosphere are believed to exert a cooling influence. This will be transitory.

Global warming due to any forcing has a built-in delay due to the vast heat capacity of the earth. With such a rapid ramp up of CO2, the increase in surface temperature will certainly be delayed by a large amount.

“However, the fact that Willis easily deconstructed Shakun’s flawed methodology means nothing to the tribalist alarmist crowd, which as usual completely ignores the scientific method — just as they ignore the central fact that a warming ocean outgases CO2, not vice-versa. CO2 is not warming the oceans; warming oceans are outgasing CO2. But try to explain that simple fact to the true believer alarmist crowd.”

Once again you show that you are incapable of thinking clearly. You have argued a false disjunct. The fact that a warming ocean outgases CO2 does not imply that CO2 cannot warm the ocean. In fact both things are true. Try to explain that to the so called “skeptic crowd”, like Smokey.

Eric Adler seems to actually believe that a warming ocean does not outgas massive amounts of CO2 into the atmosphere. Adler is consumed by his incurable cognitive dissonance, wondering like Orwell’s Mr. Smith: if enough people believe that 2 + 2 = 5, does that make it true?

In fact, warming oceans do emit massive amounts of CO2, despite Adler’s crazed disbelief. That outgassed CO2 is added to the atmosphere, exactly like a warming beer emits CO2 and adds it to the atmosphere.

Adler’s psychological projection causes him to point to other rational actors, falsely claiming that they are ‘incapable of rational thought’. Obviously, there are no mirrors in Eric Adler’s mom’s basement.☺

The data were projected onto a 5°x5° grid, linearly interpolated to 100-yr resolution and combined as area-weighted averages.

I have several problems with that procedure, which I may write about later.
”

Ah, this explains a lot. So the more reliable, less noisy ice core proxies from both ends of the planet have their influence on the ensemble severely down weighted the area weighted mean. It also means that they are interpolating between the apples and the oranges.

With so many of these proxies clearly bearing little resemblance to each other, what possible logic allows interpolating between them? And what possible point is there in making a grid? That is done with surface temps in order to provide a reference for climate models but I see no sense or value in doing a grid here.

Clearly the data that correlate best with the ice core derived CO2 is the ice core temp proxies, they are doing all they can here to muddy the waters by malaxing all the data. It is obvious even to naked eye that their mean does not well represent the data.

So, as always where is the uncertainty estimate? I doubt you could even estimate an uncertainty that would result from that kind of processing. It would certainly be far larger than the phase difference between the two signals that they are aiming to evaluate.

If it does not have a proper uncertainty estimate, it is not a scientific result. Simple.

Sadly this is yet more cargo cult science getting accepted by uncritical pal-review.

Several people have said that orbital forcings are the reason for the decline in temperature over the holocene. As the earth goes around the sun, over time the eccentricity and the obliquity of the orbit slowly changes.

The problem with this theory is that the orbital forcings change the distribution of the sunlight, but barely change the total sunlight at all. Since there is no change in TOA insolation, why would that cool the earth?

I could see where earth with a low obliquity would have more stable atmospheric systems controlled by latitude with no seasons. I would suspect warming flowing consistently towards both poles year long. This may not change much at extreme latitudes but could reduce the coldest circumference by extending warm some degrees toward both poles.

Willis is quite correct to suggest that the proxies need to be looked at individually as he has done. (If one were asked to describe a picket fence and had data on 80 picket fences, any one fence is far more useful than any notion of an average picket fence. Averaging always destroys some information, often useful information.)

Others writing here have made comments along the same lines. Here I am just suggesting a simplified way of looking at this.

Let’s (over)simplify things. Suppose each of the 80 proxies is an instantaneous temperature step in time and that the step times are uniformly distributed in time from something like 15000 BC to 5000BC. Averaging would give a ramp (in small steps) from 15000 to 5000. Now, more realistically, the transition step times might be normally distributed, and now the average would look sharper (not just a ramp) and would be like an integrated Gaussian.

The point is that we could easily and predictably make the transition point of the average move up or down (relative to CO2) by including or excluding outlier proxies. So if we were of a mind to “adjust” the result, we would know how to do it.

If we assume no attempt at deliberate deception, then we should still be aware of the likelihood of fooling ourselves by our particular choice of a particular set of 80 proxies. There is no obvious way to fix this problem in general and even less hope in the case where the times range over 2/3 of the overall time period considered.

It’s a hopeless, disparate mess. Willis said it simply: “It’s all over the map.” Indeed.

andyd on April 8, 2012 at 2:54 pm said:
Lazy, I am trying to understand which graphs you are referring to.
———-
All figures . But I have figured it out now. Brain was fixated on the scale being the conventional before present, except it’s actual origin is 0 AD or maybe 0 BC.

Jimbo says
Nice point, tell that to Hansen (1988) and compare to the present global mean temps. Not (yet) opposite but wrong. IPCC 1990 again wrong. Think a about it.

Ideas: Oceans, sun, inclination…………..
————
On short time scales I am not expecting temperature to track CO2 in lock step. CO2 is not the only thing affecting temperature. Ocean water turn over can produce short term variations as can other stuff.

This particular example is interesting because it is a long term effect. A few years ago one paper floated the idea that early agriculture had an effect, but I regard that result with some skepticism. This observation by Willis is consistent with that, but consistency and a demonstrated real effect requires joining dots we don’t yet have.

If you could ever get over your fixation on “carbon” propaganda, you might conclude that CO2 may not have the effect claimed. And of course there is also the well established CO2 lag time, which allows for divergence.
———-
Actually Smokey I learn most of my stuff from you skeptic guys. I read and analyse what you say, conclude you have no idea what you are talking about, and then go and find some decent physics or figure it out myself. So my actual sources are climate skeptic propaganda.

I think what the big picture shows, is that the warmist’s are looking for data to support their theory rather than analyzing the data, all of the data, and trying to figure out what it means. If you are ONLY looking for data to support your theory, it is really easy to find some. Why is it in climate science, the warmists are only looking for data to support their theory and ignoring everything else?
I think it should be standard fare now to be absolutely CERTAIN to check to see what data was left out (or altered) whenever any papers supporting AGW are published. No longer can/should they be trusted to be an objective source. The continual refusal to present (or outright hide) and discuss evidence that has a “problem” following the theory or model results in total loss of confidence to trust any conclusions they come to.
Still, whether the conclusions are right or wrong (mostly wrong or inconclusive it would seem) this study by Shakun has no effect what-so-ever on the debate on whether we need to drastically alter our way of life and standard of living. That debate is about HOW MUCH warming we can expect from rising CO2 due to use of fossil fuels, and there is plenty of evidence (as opposed to models) to suggest it will be less than 1C of warming per doubling of CO2.

Willis: If you intend to plot CO2 on a serious graph along with temperature, I suggest that you first take the log of the CO2 data (which should be proportional to any temperature change it may cause), then normalize. It may not make any difference, but you don’t want to look like Al Gore in An Inconvenient Truth rising on the lift to point out where the are headed (perhaps 1.5 doublings of CO2) on that infamous graph of temperature and CO2 vs time.

You are right, but it’s a difference that doesn’t make a difference at this level of analysis and with this amount of CO2 variation. Here’s the difference:

“My big critism would be that they should have ended both data sets at the same point, leaving the recent past to someone else’s endeavors. Nick, you would have to agree with me on this point at least.”

I’m not sure where I made any points about CO2 leading or lagging – in fact, despite the impressions of Vince Causey etc, all I’ve said is that the plots he showed covered periods that were relevant to the phenomenon that he was writing about. But on that point, despite what Willis seemed to say, the diagrams as summarised here all seem to cover exactly the same period, ending about 8K BP. And yes, that does extend at each end a bit beyond the deglaciation. You generally need to do that when graphing, just to show that the graph does enclose the required period.

sophocles says:
April 8, 2012 at 12:35 am
Phillip Bradley says:When temperatures fell during the YD, CO2 just stopped rising.
====================================================
and phlogiston says:
It is curious how CO2 flatlined during the Younger Dryas.
====================================================

… there should be GCR/Solar activity proxies for the same period which can indicate what else
was happening.

I can see the sun waking up, or the GCR count dropping—or both—BEFORE the big melt started. The clouds roll back and the ice begins to melt. Then the CO2 starts to rise as the oceans warm …

wmconnolley says:
April 8, 2012 at 12:48 amWandering off in conspiracy land again I see. You need to read Eric Wolff

Indeed the data on CO2 and temp proxies is complex and one cant necessarily snatch at easy conclusions.

However the elephant in the room here is the Younger Dryas (YD). As commented above, during the YD temperatures fell (as shown by the ice cores and better proxies) but CO2 did not. To anyone genuinely interested in reasons for global temperature change and with an open mind as to the role of CO2, this YD observation should be of huge interest as an important clue.

Here is a possible explanation:

1. Ocean temperatures drive major climate shifts such as between glacial and interglacial, and as such, oceans started warming about 20 kYa.

Eventually the longer term ocean driven warming overcame the YD event and the Holocene interglacial became established.

4. Thus in general ocean driven climatic temperature changes will have a CO2 signature (related to ocean CO2 solubility) while atmospheric driven temperature changes will not (except insofar as they affect the ocean).

Shakun et al have exploited the extra complexity added to the Holocene initiation by the Younger Dryas to conjure evidence for a temp lag, for political ends. I described this earlier as the “Younger Dryas two-step”. However the real interest in the start of the Holocene and the YD is in the clues it provides concerning the causes and driving of global climate shifts in general.

The “logic” of Shakun et al. is well described by Piers Corbyn:

What they’ve done is like mixing apples and oranges and leaving them to rot.
The apples rot first giving off a stink and the oranges rot later. You see that most of the fruit –
the ‘average’ – rotted after the stink started and conclude: The stink caused the fruit to rot.

Finally – the uptick in CO2 reported here by Willis in the latter part of the Holocene (coinciding with declining tempereature) could be a long term ecological consequence of de-glaciation such as slow melting of permafrost, methyl clathrate ocean releases etc. The opposing rise of CO2 and fall in temperatures point further to the impotence of CO2 as a climate driver. This role is played by the ocean.

While I am happy to believe that the bistable oscillations observed over the last half million or more years are coupled to astronomical cycles, that does not suffice to explain the bistability. There is a causal factor missing.

A nonlinear oscillating system does not need an external forcer to exactly drive its transitions – such dynamics can come from within the system with no external driver and no apparent cause. Consider the Belousov-Zhabotinsky oscillatory reaction for example. That said however, although some nonlinear oscillators are non forced, others are externally forced, and they fall into two categories – strongly and weakly forced.

Our heartbeat is a nonlinear oscillator which is normally unforced and generates its own frequency, however in heart disease where this internal forcing breaks down external strong forcing can be provided in the form of a pacemaker. This is strong forcing – heartbeat follows the pacemaker. However there are also weakly forced nonlinear oscillators where there is no clear relationship (or a very complex relationship) between forcer and emergent nonlinear oscillation.

It seems to me most likely that climatic oscillations between for instance bistable glacial and interglacial attractors, is weakly forced by astrophysical orbital forcings and possibly solar cycling also. Making it very hard to link the oscillation to the forcing, even though the bistable signature is very clear. For instance 1 million years ago the bistable oscillation flipped from following the 40 kYr inclination wobble forcing to the 100 kYr eccentricity cyclic forcing. This flipping between two drivers suggests weak nonlinear forcing in the context of multiple weak forcers.

Septic Matthew/Matthew R Marler says:
April 8, 2012 at 11:12 am
Volker Doormann: “Science is to show agreements in nature, not to being skeptic on possible agreements, because skeptic is not a method of science.”

Science is unique among the ways of knowing in its great respect for skepticism.

That is not an argument, but a personal belief statement, and therefore not a valid method of science; arguments always are related to reasons not to an *Ism.
Willis says, he belief nothing, but that shows no knowledge.

Other approaches emphasize faith, but scientists accept as possible truths only those assertions that survive extensive skeptical challenges.

What scientist, you claim, accept, is not relevant, because truth is not an eigenvalue of social groups.

The claim ‘extensive skeptical challenges’ is a fraud, because skeptics never have shown what IS; moreover they never have been skeptic on skepticism. It is a nonlinear method like politics, morality, power of authority and/or government people, or claims idol power in blogs to non-followers.

There is a fact: The solar tide function of the two celestial objects Quaoar and Pluto correlates with the changes of the temperature proxies in the ice core records in the Antarctica over a time interval of 5000 years; here the correlation in the phase and time coherence is better than the correlation of the magnitude.

This fact is an independent scientific fact. It is a scientific fact, because it is a fact from geometry and geometry is a method of science. No skeptic, no peer of authorities can make this fact untrue.
Leif Svalgaard as a member of a peer says:“Volker Doormann says: This proves nothing more than that a solar spring tide is in phase with global high sea level.”
Mercury is as relevant as my flat tire. Has no effect whatsoever.”

This is a classic example of skepticism, because it claims NOTHING, and it ignores by the claimed authority of a peer the fact, that the solar tide function of Mercury as a part of the high frequency temperature oscillations measured by UAH shows strong correlations but also in the sea level oscillations.

Your claim of skepticism is not a claim of science, but a claim on judgment in a hierarchy of peers, layman, and plebeian. Science is an open garden without nonlinearities to discuss facts and to find the rules of the one nature. No invalid argument out of hundred processed by clean tools to errors gives truth.

I do not know why people are fighting against an unvisible gost molecule like Don Quixote against wind mills, while a lot work have to be done answering the questions to the cause of heat boost jump of ~8° Cel after any ice age. This is especially relevant, because the FFT analysis of Bolshakov of the ice core data, shows power peaks which have a geometric and physical relation to possible resonant modes in the Sun.

Acheson says
I think what the big picture shows, is that the warmist’s are looking for data to support their theory rather than analyzing the data, all of the data, and trying to figure out what it means. If you are ONLY looking for data to support your theory, it is really easy to find some.
——–
Errr, what theory would that be?

All of these changes in CO2 and temperature are occurring before human civilization started. Which means that there is no anthropogenic CO2 to speak of over this period. Which means there is no AGW prediction that during these prehistoric periods CO2 increases will preceded temperature rises.

In fact the prediction is the opposite. Solar Insolation charges cause temperature rises which cause CO2 rises which in turn amplify the temperature rise in positive feedback. AGW theory has it that temperature rises are expected to precede CO2 rises in the post ice sheet time frame.

When you find periods where the two ( GHGs and temp) do not move in concert, you know one thing: all other things were not equal. You don’t know and you can’t know that GHGs dont increase warming. You dont and cant because fundamental physics is correct. We known that its correct because we building working devices based on that physics.

Classic fallacious ‘petitio principii’, “begging the question”, affirming the consequent argument. It is astonishing to think that those who work or write about science know so little of logic, philosophy and history that they can make such a claim.

“fundamental physics is correct. We known that its correct because we building working devices based on that physics.”

We know nothing of the sort from embracing fallacies such as affirming the consequent. Both Laplace and Carnot believed that heat was an imponderable fluid, ‘caloric’. The steam engine was a working device based on such faulty fundamental physics, as were the seemingly correct thermodynamic predictions of the day. Other examples are legion. Seemingly accurate predictions and working devices have been based on faulty physics for centuries. The instrumental use of current physical theories to produce working devices in no way proves that fundamental physics is correct. Oh, yes, science can be very useful in an instrumental sense to engineers and technologists, but ‘fundamental physics’ is not and never has been ‘correct’ since it is always changing. Our so-called ‘physical laws’ are only ever imperfect models of reality, mere human abstractions from limited data and understanding, and often quite tentative and ephemeral.

=> Politely ask all the co-authors of this Nature paper if they were really aware of what they put their names too (preferably via someone who knows them).

=> Could the Gentlemen of Nature show us bursts in CO2 levels which precede solar events such as the large Coronal hole at the centre of the solar disc today (April 9th) as forecast – and which is a driver of weather and likely earthquake events?! See pic of
Large Coronal Hole heading for center of Suns disc today as we warned: http://spaceweather.com/archive.php?day=09&month=04&year=2012&view=view
and our forecast which apart from weather events also says Major Quakes are likely to come in the present period (~8-10th) as a consequence of this coronal hole and related solar eventshttp://climaterealists.com/index.php?id=9413

Nature’s editorial “So let there be no confusion now: the new study confirms that, as Earth emerged from the last ice age some 19,000 to 10,000 years ago, rising global temperatures were preceded by increased global carbon dioxide in the atmosphere — a result that emphasizes the role of carbon dioxide in driving global change in the present day. This relationship is a foundation stone of climate science and of policies to regulate greenhouse-gas emissions, and it is solid.”

Can this possibly be written by educated scientists? I think not. Even if it were the case that ‘rising global temperatures were preceded by increased carbon dioxide in the atmosphere’, which, looking at all the data underlying the paper is certainly not proven, this in no way implies causation, so it is folly to assert that this ‘confirms’ and ’emphasizes’ that ‘carbon dioxide is driving global change in the present day’. That does not follow from the data, and it is an unscientific observation.

This relationship is said to be ‘solid’, and the ‘foundation stone of climate science’ and the expensive public policies. However, it is dangerous to use words such as ‘solid’ in the scientific enterprise. A ‘solid foundation’ is one that will support a building, such that even if the building is modified or even rebuilt the foundations remain. With this metaphor, the relationship that global temperatures always follow CO2 changes is one that cannot be questioned because it is so fundamental. This is a dangerous place for any editor to be in in a supposedly scientific journal, for he will be minded to reject papers that robustly demonstrate otherwise, and accept feeble and ill-conceived papers that support the assertion.

Science does not progress by having touchstones of truth, tests of orthodoxy, unchallengeable doctrines and the like. True, extraordinary claims require extraordinary evidence, but let’s not close our minds to what can be admitted as evidence in the first place. Such prejudice is the way into a scientific dead end.

One thing that struck me was the similarity of the CO2 response and the transient response of a cro probe that has not been adjusted properly. For example see here.http://www.analogzone.com/tmt_0314.pdf

But I also started to think about the CO2 as having different sources with different time constants.

The temperature readings are also local perhaps’ with some being affected by water vapor feedbacks more than others. Near the poles, little water vapour, near the equator lots, thus CO2 levels having less direct influence as time goes on. Have not convinced myself at this stage.

“Eric Adler seems to actually believe that a warming ocean does not outgas massive amounts of CO2 into the atmosphere. Adler is consumed by his incurable cognitive dissonance, wondering like Orwell’s Mr. Smith: if enough people believe that 2 + 2 = 5, does that make it true?”

Smokey,
I never said anything of the sort! I said that the fact that warm oceans outgas CO2 doesn’t mean that CO2 cannot warm the oceans as you claimed in a post above. This is a false contradiction.

If you are being serious here, it is clear that you don’t understand logic or you cannot read. Ignorant posts such as yours deserve to be ignored.

[…] So the current change in CO2 represents a comparable forcing factor to the deglaciation.

Maybe we should work on tripling the CO2 contribution to the atmosphere, then, so the temperatures will actually go UP instead of declining.

That, or your hypothesis is incorrect.”

Your ignorance of climate science is showing. You seem to be referring to the recent slowdown in global warming. It is well understood that internal variation during such a period can overcome the global warming trend due the GHG’s. In addition sulfate aerosals, which have a short lifetime in the atmosphere are believed to exert a cooling influence. This will be transitory.

Global warming due to any forcing has a built-in delay due to the vast heat capacity of the earth. With such a rapid ramp up of CO2, the increase in surface temperature will certainly be delayed by a large amount. Ah, the nasty ad hom, eh? It very well could be that you’re conveniently forgetting the earth has been warming since the LIA, most of which warming came about with little or no benefit of anthropogenic CO2. Or was this past warming (according to some “Back to the Future” CAGW thinking), magically due to the higher levels of CO2 we’re seeing now?

You concentrate on one miniscule point which I didn’t make and fail to see the bigger picture. (I love setting traps, Eric; you’ve been caught).

This is science not political word games. If there is data at hand that confirms or calls into question the basic underlying arguments surely it sould be presented. But I guess a little bit of doubt doesn’t get you into Nature.

I think I can thoroughly dispell Willis’ denialists whining with a simple quote from Einstien:

(paraphrased so I don’t have to go look it up, ’cause we don’t look stuff up when we talk about climate, don’t you know.)

From Einstien:
“Countless exceptions to the theory of relativity may indicate that I am wrong, but if I can get enough examples of cases where observations match my theory into the news, then people will believe me anyway.”

Well, that’s paraphrased, but it’s close enough for Team Nature.

That was a joke, of course. On the serious side, my above fake “quote” seems to a strategy that works for just about any cause you can name. Special interest groups use that tactic with brutal effectiveness every day. Too bad there’s not a special interest group who looks out for America’s #1 endangered species: middle class working families (not sure what the Latin for that is).

“All of these changes in CO2 and temperature are occurring before human civilization started. Which means that there is no anthropogenic CO2 to speak of over this period. Which means there is no AGW prediction that during these prehistoric periods CO2 increases will preceded temperature rises.

In fact the prediction is the opposite. Solar Insolation charges cause temperature rises which cause CO2 rises which in turn amplify the temperature rise in positive feedback. AGW theory has it that temperature rises are expected to precede CO2 rises in the post ice sheet time frame.

This paper contradicts that theoretical expectation.”

In fact it does not contradict it. Temperature rises in the Southern Hemisphere did precede the rise in CO2, and further increases in global temperature resulted from that. The author says:

“These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.”

It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.

The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?

“You concentrate on one miniscule point which I didn’t make and fail to see the bigger picture. (I love setting traps, Eric; you’ve been caught).

So I shall repeat: “That, or your hypothesis is incorrect.””
Crowing about your own brilliance is silly. Your point was that currently the earth is not warming.
That is a common argument used by so called “skeptics”, has been answered over and over again, and represents a failure on your part to look at the bigger picture.

[SNIP: Eric, if you have an argument, make it here. We are not directing traffic to an unreliable web site. -REP]

Cumulative summing of errors is known in machining, for example. If you have a line of four holes with a tolerance of +/-0.005″ on the spacing between the holes, then 3 spaces times +/-0.005 yields possible positional error between first and last holes of +/-0.015″. Likewise when items of known length tolerances are stacked when figuring out overall length, be it measuring standards for reference or parts in an assembly.

Although there can be an assumption of greater accuracy. For example, if it is assumed the measurements will fall at the middle of the tolerance, then the probability of summed measurements being at the middle of the summed tolerances grows. If the machinist was to be trying to hold +/-0.002″ on three measurements of +/-0.005″, as normally you stay away from the limits, then it is probable that the sum of the measurements is around +/-0.006. You might be able to argue it is likely better than that, as you could have two measurements on the positive and one on the negative which cancels out some error, and it is more likely for three to have two on one side and one on the other than all three on one side, etc.

In reality smart engineers and draftsmen know better than to assume and specify the overall accuracy as absolutely required. It fits or it doesn’t, assuming it probably will doesn’t work. But in a fuzzy wishy-washy field like Climate Science™ when backed with the pliant statistics of probability, I can see how they can claim greater accuracy.

It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.

The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?”

If you look at the temperature curves in figure 2a of Shakun’s paper, you see that the Younger Dryas event did not hit both hemispheres in the same way. The Southern Hemisphere temperature started to decline while the Northern Hemispere was rising and vice versa as time proceeded. So the average global temperature plateued, as did the CO2 concentration, between 15KyBP and 13KyBP. So if you look carefully, your objection disappears.

The major point made by Shakun2012 is that temperature changes in the Northern and Southern hemispheres are offset, so that the lag between global average temperature and CO2 is less than the 800 year lag between Antarctic temperature and CO2. Simulations show that CO2 was driving the temperature increase during that periond. The behavior of global average temperature and CO2 during the Younger Dryas does not contradict that point.

Phlogiston says:
“However the elephant in the room here is the Younger Dryas (YD). As commented above, during the YD temperatures fell (as shown by the ice cores and better proxies) but CO2 did not. To anyone genuinely interested in reasons for global temperature change and with an open mind as to the role of CO2, this YD observation should be of huge interest as an important clue.”

You are wrong. Global Temperatures and CO2 plateaued. The temperature changes see sawed between the two hemispheres during the Younger Dryas. Check the fig 2a of Shakun’s paper.

REPLY: LOL! Just because Shakun says so in one paper doesn’t make it true, unless of course you are an unquestioning true believer like Mr. Adler – Anthony

Philip Bradley (and others) complained that my link (http://scienceblogs.com/stoat/2007/03/yet_more_tco2_lags.php) starts with text clearly contradicted by what WE has shown here. First, thanks for reading, and pointing out the apparent problem. EWW is a scientist, not a lawyer. I’ve updated the text into a form that should make you happy.

Second, and more important, we don’t have a global temperature record for the holocene, so the claims here of CO2 up while T goes down are premature. CO2 goes up (a little bit) and we know that is global, so that is fine. But a scatter plot of proxies smoothed by eye is not a temperature record, so you fail on the “T goes down bit”. AFAIK there is no recognised global (or hemispheric) temperature record for the holocene, or for the last 6 kyr. If you think you have one, and can justify it, that would be publishable.

That leaves two things: the people calling WE’s post “brilliant” and pressing him to publish it; and those calling on Nature to retract Shakun because of it. The latter is nonsense, as NS has already said: this post doesn’t contradict Shakun. The former is badly out of touch with reality: all WE has done here is draw the CO2 record (which is already well known) and created something that looks to amateur eyes as though it could be a temperature record. But there is no way you could get that past real journal review.

I would confront the author of the study with your findings, Willis, and ask him to withdraw or repair/amend his paper, before writing a comment to Nature. But that’s only the way we would handle errors in software development if the review-process hasn’t found them. I’m not sure, wether this is correct in science as well……

I would confront the author of the study with your findings, Willis, and ask him to withdraw or repair/amend his paper, before writing a comment to Nature. But that’s only the way we would handle errors in software development if the review-process hasn’t found them. I’m not sure, wether this is correct in science as well……

A number of folks have suggested I write up a comment for Nature regarding this study. You suggest I write the author and write to Nature. I likely won’t do either one, for several reasons.

The first is that writing scientific papers is a pain in the fundamental orifice. If I’m going to do it, I’ll do it for some independent scientific analysis that I’ve done. For me, it’s not worth doing just to falsify someone else’s work. I’ve done that in the past, but now I have other interests.

The second is that most of the scientific players who would read such a “Communications Arising” in Nature read WUWT as a part of their daily fare. If you are a serious player in the climate game, you read WUWT, and Climate Audit. Even the avid AGW supporters read WUWT and Climate Audit, just to stay ahead of what the opposition is saying.

The third is, I’m not writing for history. I’m not writing to establish my scientific credentials. I don’t have to publish or perish. I write in order to influence the ongoing scientific dialog, and that dialog has moved and is moving even further onto the web. From my own experience with “Communications Arising” in Nature, it takes some months before my study would appear … and by then, the scientific discussion has moved way beyond whatever my study was about.

The fourth is eyeballs. My work on WUWT draws about a million page views per year.

Now, this doesn’t mean that I don’t want to publish in the journals. I do. There’s three or four things I would love to see published. My cluster analysis of the Mann proxies. My analysis of the tropical tropospheric hot spot. My work with the TAO buoys. My investigation of the maximum ocean temperature through the Argo floats. All of those are valuable, valid original scientific work.

But just for dis-assembling shabby science like this? Not worth the effort to get it published, for me. If someone wanted to work with me to get a “Communications Arising” published in Nature, I’d work with them, but to do it myself is not worth it.

… we don’t have a global temperature record for the holocene, so the claims here of CO2 up while T goes down are premature. CO2 goes up (a little bit) and we know that is global, so that is fine. But a scatter plot of proxies smoothed by eye is not a temperature record, so you fail on the “T goes down bit”. AFAIK there is no recognised global (or hemispheric) temperature record for the holocene, or for the last 6 kyr. If you think you have one, and can justify it, that would be publishable.

What I have is eighty proxies that go down over the Holocene by about a degree or so. I know you don’t like that, but there it is. Claiming that they are “smoothed by eye” is nonsense, they are not smoothed at all. They are standardized and displayed. Period.

Do those 80 proxies comprise a “global (or hemispheric) temperature record”? Well, the authors of Shakun2012 argue very strongly that it is both, so you’ll have to take that up with them …

Thank you for your quick answer, Willis. I understand and respect your reasons. All I wanted to ask for, was to drop the link of this thread into the authors mailbox, that should be enough, since you published your work here…..I hope I find the time to read your love-to-be-published studies!

Philip Bradley (and others) complained that my link (…) starts with text clearly contradicted by what WE has shown here. First, thanks for reading, and pointing out the apparent problem. EWW is a scientist, not a lawyer. I’ve updated the text into a form that should make you happy.

It is indeed a very fundamental question about whether the CO2 leads or lags the temperature. If there was somewhere in the ice core record where CO2 increases and temperature does not, then our understanding of the greenhouse effect must be faulty. However, so far we don’t find such a place.

Unfortunately in detail the phasing between CO2 and temperature rise is a difficult question to answer. (…)

Updated:

Guest posting by (or rather, ripped from) Eric Wolff.

It is indeed a very fundamental question about whether the CO2 leads or lags the temperature. If there was somewhere in the ice core record where CO2 increases and temperature does not, then our understanding of the greenhouse effect must be faulty. However, so far we don’t find such a place. [*]

[*] Eric is a scientist, not a lawyer. His words, whilst essentially still valid, were not carefully enough framed. He writes (2012/4): I should have carefully included the words “all othe things being equal” and “significantly” as in: “If there was somewhere in the ice core record where, all other things being equal, CO2 increases significantly and temperature does not, then our understanding of the greenhouse effect must be faulty. However, so far we don’t find such a place”. This is to cover the case of the last 6 kyr-to-preindustrial, where CO2 has risen a bit (though very little, by comparison with iceage-interglacial changes), and T has stayed more-or-less-flat.

Unfortunately in detail the phasing between CO2 and temperature rise is a difficult question to answer. (…)

Something falsifiable and absolute was stated back in 2007, Willis Eschenbach falsified it, so you “updated” it to remove the inconvenient falsifiable-ness.

By the terms originally posited five years ago, that you posted on your blog without objection, Willis Eschenbach has conclusively demonstrated that your knowledge of the greenhouse effect must be faulty. So now you “update” those terms with additional weaselly-ness (as appropriate for a stoat), and proclaim ‘Ah-ha, it didn’t happen, Eschenbach hasn’t proven anything!’

Wow. So now in addition to Mike’s Nature trick, we have Connolley’s “As true as it ever was!” trick. So noted, so remembered.

Thank you for pointing out that Willy is as ethics-challenged as Peter Gleick. IMO neither one is honest. An honest man would have admitted his error, or at the very least, kept quiet. But as the Wikipedia Chief Propagandist, Connolley is used to altering the record. His self-identity as a weasel is appropriate.

“It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.”

If you look at figure 2a in the Shakun paper, during the Younger Dryas, the temperature drops were not simulataneuos in the 2 Hemispheres. As a result The global temperature did not drop; during the Younger Dryas, it stayed constant during this period. This is simple to see from the graph by taking the average of the two hemispherical temperatures.

The 80 proxies representing different regions of the earth do not behave simultaneously. They should not be expected to. The ocean currents are constantly shifting. Your adjective convenient has absolutely no meaning here. Proxies do not understand the concept of convenience. Proxies are not humans.engaging in a conspiracy to deceive global warming skeptics.

You wrote further,

“The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?”

It is clear from your reply that you didn’t follow, or care to follow, my answer to this question, and are asking it again. Your objection seems to be that the proxies are engaged in a conspiracy to deceive global warming skeptics. Are you for real?

As Anthony correctly pointed out, Adler is an unquestioning true believer. Adler is also wrong. He tries to claim that because hemispherical temperature variability is not simultaneous, Shakur et al. remains unfalsified.

But that is a strawman argument. As we see here, global temperatures never occur in lock step [lower chart]. But we do see that global temperature variability is highly correlated between the hemispheres.

Willis has done an outstanding job of deconstructing the shaky Shakur paper in his series of articles. Obviously Shakur et al. was simply hand-waved through pal review without the least bit of scrutiny. It is an ugly turn of affairs when once reputable journals become politicized pseudo-science enablers, but that is in fact what has happened. The result is that fatally flawed papers give mindless cheerleaders and alarmist lemmings something to rally around, as we see above. And true to form, they totally ignore the scientific method.

Adler fits the description of Orwell’s Winston Smith, who wonders: if enough people believe that 2 + 2 = 5, does that make it true? Believing in Shakur et al. does not make it true, and in fact most research papers are false. Shakur is in the majority there.

“Second, and more important, we don’t have a global temperature record for the holocene, so
the claims here of CO2 up while T goes down are premature. CO2 goes up (a little bit) and we know that is global, so that is fine. But a scatter plot of proxies smoothed by eye is not a temperature record, so you fail on the “T goes down bit”. AFAIK there is no recognised global (or hemispheric) temperature record for the holocene, or for the last 6 kyr. If you think you have one, and can justify it, that would be publishable.”

I have seen graphs of average global temperature during the holocene period. It seems there have been a number of different reconstructions; and the temperature does seem to go down a bit since 7500yBP. It does appear that there is a lot of disagreement among the different reconstructions regarding details so it does seem that a solid new reconstruction would be well worth a publication.

In a previous post, I pointed out that the rise in CO2 is only about 8%, and the forcing from it would be small. If the standard estimates of climate sensitivity, 3C are correct, CO2 by itself , would increase global average temperature by about 0.3C. During this time period, the orbital and axial forcing is acting to reduce global temperatures. The actual drop in global temperatures appears to be a few tenths of a degree C. This is small compared with the 3.5 C rise in temperature during the period of deglaciation, which is obviously a lot easire to model. In fact, CO2 during that period of time increased by 86% which is almost a doubling, so this is consistent with the most common estimate of climate sensitivity.

“Adler fits the description of Orwell’s Winston Smith, who wonders: if enough people believe that 2 + 2 = 5, does that make it true? Believing in Shakur et al. does not make it true, and in fact most research papers are false. Shakur is in the majority there.”

[snip] One could just as well argue that Eschenbach’s critique is one of the majority of papers which are wrong!

“It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.”

If you look at figure 2a in the Shakun paper, during the Younger Dryas, the temperature drops were not simulataneuos in the 2 Hemispheres. As a result The global temperature did not drop; during the Younger Dryas, it stayed constant during this period. This is simple to see from the graph by taking the average of the two hemispherical temperatures.

The 80 proxies representing different regions of the earth do not behave simultaneously. They should not be expected to. The ocean currents are constantly shifting. Your adjective convenient has absolutely no meaning here. Proxies do not understand the concept of convenience. Proxies are not humans.engaging in a conspiracy to deceive global warming skeptics.

You wrote further,

“The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?”

It is clear from your reply that you didn’t follow, or care to follow, my answer to this question, and are asking it again. Your objection seems to be that the proxies are engaged in a conspiracy to deceive global warming skeptics. Are you for real?

Due I think to delays in appearance of some of my postings, all your replies to my posts appeared after all my posts – so this is my first change to answer your comments – I did not see them before.

It would appear you are trying to deny the existence of the Younger Dryas – rather like other well-known AGW denials of for instance the MWP and LIA. The YD is defined as a transient fall in temperatures as shown in ice core and other records. You are not contradicting my argument – that two temperature rises before and after YD but the reactive CO2 increase flat-lining during the YD allows the later, post-YD part of the temperature rise to be claimed as responsive to CO2. Instead you appear to be casting doubt over whether the YD was real or not – a YD temperature pause only, not fall, is not really a YD.

This addresses the main point of Willis’ initial “Munchausen” post – that there is so much variation between all 80 proxies that the merged result scarcely confirms the Holocene’s existence, let alone the YD. Many of these proxies are biological and relate to ecological factors of ecosystem development at the start of the interglacial. They thus are poor direct indicators of temperature. The approach of combining all 80 is not an approach aimed at clarifying what went on, but the opposite – it is aimed at obscuring it.

The same can be said for the argument you repeatedly make about the non-synchrony of the two hemispheres. If they are non-synchronous, then WHY MERGE THEM? – why not study them separately? In scientific analysis of difficult and variable data we seek to minimise confounding variables, not maximise them.

In a court of law evidence is rigourously filtered for its quality. Allowing equal footing for a crowd of “shaky” witnesses would allow every criminal off the hook. We in scientific research need equal rigour – the 80 proxies should be ranked in reliability and only the best few of them selected for actual temperature reproduction. And if the hemispheres behave differently, then better resolution is achieved by studying them separately. The results from north and south can be looked at in parallel, for instance in interpreting global CO2, but merging them together does not advance truth.

A nonlinear oscillating system does not need an external forcer to exactly drive its transitions – such dynamics can come from within the system with no external driver and no apparent cause. Consider the Belousov-Zhabotinsky oscillatory A nonlinear oscillating system does not need an external forcer to exactly drive its transitions – such dynamics can come from within the system with no external driver and no apparent cause. Consider the Belousov-Zhabotinsky oscillatory reaction for example. That said however, although some nonlinear oscillators are non forced, others are externally forced, and they fall into two categories – strongly and weakly forced. reaction for example. That said however, although some nonlinear oscillators are non forced, others are externally forced, and they fall into two categories – strongly and weakly forced.

Perhaps I should have been more explicit. The Earth is describeable in the coarsest of terms by a differential system that is almost identical in structure to the one I studied years ago in the context of nonlinear laser optics (perhaps without the resonant structure). It is an open system with a known primary driver — Mr. Sun. Energy in, energy out, energy trapped, and some sort of internal feedback that switches the system from a state with large amounts of stored energy to one with smaller amounts of stored energy.

In the case of optical bistability — where the Earth as noted is a large, complex, optically bistable oscillator — bistability is caused by the absorbing atoms in a resonant cavity becoming transparent as their mean excitation increases and they start to be driven through complete Rabi cycles — it is a resonance phenomenon. In the low excitation (opaque) state, atoms remain in a state such that spontaneous emission can keep up with excitation. Such a system exhibits classic first order transition behavior and hysteresis with two stable branches over certain ranges of the external driver.

In the case of the Earth, the simplest model is a greybody — sunlight in, some reflected by the albedo, some absorbed, all that which is absorbed reradiated via blackbody radiation to equilibrium. No possibility of bistability barring a stable modulation of albedo. Add an atmosphere (with GHGs) and you warm the planet relative to greybody but still everything is in balance, and unless you have nonlinear feedback of either albedo or the GHGs themselves you still don’t have bistability. Add oceans, add circulation, add mountains, deserts, currents — add the moon (which alters vertical mixing of the oceans), add sources and sinks of GHGs and aerosols, add the fact that the Sun is a somewhat variable start — and we have an embarrassment of riches. Somewhere in there we did enable sufficient nonlinearity to facilitate bistability, but we still cannot even describe the system well enough to capture the locally linear behavior in the stable mode. Worse, there are periodicities such as 110,000 years in the bistable oscillation frequency, and the warm mode behavior is in some ways “like” the temperature 3 million years ago when everything was different — especially oceanic circulation patterns through the still open panama seaway.

So yeah, I agree that there is enough interesting and complex physics for bistability to arise without an external major nonlinearity but — I doubt it. Not with the quasi-periodic behavior observed. The dimensionality of the solution isn’t that high, at least not in the last half-million to million years. Understanding the critical control dimension is key to resolving the probable near-term behavior of the climate, which is a necessary prior to being able to predict the behavior of the climate system as it responds to e.g. increased CO_2.

A lot been said here, a lot beyond my scope, but intriguing nevertheless. For me this simple statement is a gem:

BernieH says:
April 8, 2012 at 9:35 pm

Averaging always destroys some information, often useful information.
– – – – –
This points to a very fundamental phenomenon in all science, not just statistics. Aggregating data and deriving patterns or formula’s or even laws at the same time always is a sifting process necessarily discarding a lot of “non-relevant” data or information. And the more you focus, the more you will leave out. This is not a mere peculiarity to ponder for amusement, it has deep consequences. If not realized it gives grave misconceptions. Like the well known statement: “ the whole is more than the sum of its parts”. This idea is everywhere, but that doesn’t mean it is right. It is wrong. Actually, it is the opposite: the whole is less than the sum of its parts.
This is so for two reasons. The first being “the whole” as an abstraction leaves out may of the peculiarities of the parts by definition, so basic mathematics makes this principle clear. The second reason being the parts always at the same time belong to may other sets outside the scope of the current investigation or discipline. From the perspective of the conceived “whole” a part is a mere object to aggregate or manipulate. But the part itself as a unique phenomenon has an almost infinite multi-dimensional richness, belonging to many many different sets. So you not only lose sight of many aspects of the part itself and their unique combination giving it “individuality”, you also loose sight of the many other sets it belongs to.
A humbling insight for any science. I know this line of thought is a bit OT in this thread, but as doing science the proper way is so central in many discussions on WUWT I might as well put it forward here. These intrinsic limitations give fragility to the theoretical scientific edifice. The more reason to be very dedicated and true regarding scientific procedures. And be very careful if not humble in your conclusions and generalizations. Nature’s editorial shows a lot of hubris. It’s about time Nature goes back to its origin: nature itself.

“Our records reveal both similarities and differences between the successive interglacial periods. They suggest the lead of Antarctic air temperature, and of atmospheric greenhouse gas concentrations, with respect to global ice volume and Greenland air-temperature changes during glacial terminations”

This latest paper just adds more detail to the understanding of the process. CO2 lags temps in the Southern Hemisphere, and leads temps in the Northern Hemisphere during the glacial temination. The general picture is not new at all, it’s just that people spinning the story for skeptical audiences have always omitted the parts of earlier studies (CO2 leads in the North) that are confirmed by the recent one.

To the best of our knowledge, deglaciation events are triggered by changes in insolation from lower to higher latitudes. The warming is not limited to the regions receiving more insolation, but is global. Both poles AND the sub-tropics and tropics all warm up at around the same time. If not well-mixed CO2, what mechanisms, in the minds of critics, are supposed to convert a local change in insolation to a world-wide change in temperature? Unless someone has a good theory about how the whole world heats up from insolation changes in specific regions, then it’s obvious that CO2 rise will lead temps in some parts of the world during transitions. It just makes sense.

Barry, I can understand your argument, that CO2 and temperature changes may differ in order in different regions, and how that doesn’t necessarily enable any side of the debate to claim anything. What it does say though, that even if one of the regions has CO2 lagging temoerature, this falsilfies any direct causation by CO2 on temperature, there must be other forces/factors in play that are/can be dominant. This is the central issue of all the CAGW debate, whether CO2 drives temperature or not.

A lot of my posts on this thread have been held up in moderation or have disappeared.
REPLY: I count 17 on this thread, and 713 comments in total on WUWT, and I’m not aware of any in moderation or that have been dropped. Bear in mind sir that you were once banned from this forum for your constant threadbombing, disruptions, and generally boorish behavior. Against my better judgement, I’ve allowed you to post again, but let’s be clear, the tolerance level for you is low, particularly when you start whining. My advice – go find something else to do for a few days. – Anthony

REPLY: I have never “disappeared” a post in all of the time I have been involved with WUWT. As to “held up in moderation”, all moderation is done by volunteers, and it is necessary to cover incoming posts 24/7/365 … so sometimes posts don’t get seen immediately. But generally, the team of moderators does an incredible and under-appreciated job of moving the comments through swiftly. – w.

REPLY: if you reload the page immediately after you post, your post will always disappear, because it has not been moderated. It will reappear after the moderators approve it. So they all “disappear”, but you’ve only noticed it a few times. -w.

rgbatduke says:
April 10, 2012 at 5:57 am
A nonlinear oscillating system does not need an external forcer to exactly drive its transitions – such dynamics can come from within the system with no external driver and no apparent cause. Consider the Belousov-Zhabotinsky oscillatory A nonlinear oscillating system does not need an external forcer to exactly drive its transitions – such dynamics can come from within the system with no external driver and no apparent cause. Consider the Belousov-Zhabotinsky oscillatory reaction for example. That said however, although some nonlinear oscillators are non forced, others are externally forced, and they fall into two categories – strongly and weakly forced. reaction for example. That said however, although some nonlinear oscillators are non forced, others are externally forced, and they fall into two categories – strongly and weakly forced.

Perhaps I should have been more explicit. The Earth is describeable in the coarsest of terms by a differential system that is almost identical in structure to the one I studied years ago in the context of nonlinear laser optics (perhaps without the resonant structure). It is an open system with a known primary driver — Mr. Sun. Energy in, energy out, energy trapped, and some sort of internal feedback that switches the system from a state with large amounts of stored energy to one with smaller amounts of stored energy.

An “open” system can also be described as a dissipative system in energy terms – again a key ingredient for emergent nonequilibrium pattern including oscillations.

Indeed the system is formidably complex and in that category where the only effective model of the system is the system itself. For this reason perhaps the best we can do is find other systems – experimental or natural (e.g. biological) with similar attributes of complexity and emergent nonlinear spatiotemporal pattern. In the light of any such systems that are better understood, look for analogies or similarities.

You say that 3 million years ago “everything was different” but it seems enough was similar for the succession of ice ages and interglacials to follow the same pattern of astrophysical forcing, with the exception of the switch from following obliquity forcing (41 kyrs) to following eccentricity forcing (the weakest of all the forcings, 100 kyrs) about a million years ago. I cant help thinking there must be some clues in this transition.

“La plus ce change, la plus c’est la meme chose”. (The more it changes, the more it stays the same).

… To the best of our knowledge, deglaciation events are triggered by changes in insolation from lower to higher latitudes. The warming is not limited to the regions receiving more insolation, but is global. Both poles AND the sub-tropics and tropics all warm up at around the same time. If not well-mixed CO2, what mechanisms, in the minds of critics, are supposed to convert a local change in insolation to a world-wide change in temperature? Unless someone has a good theory about how the whole world heats up from insolation changes in specific regions, then it’s obvious that CO2 rise will lead temps in some parts of the world during transitions. It just makes sense.

Thanks, Barry. I find this claim curious. My understanding has been that the ice ages are triggered by the Milankovich decrease in NH summer temperatures. This is said to lead to more snow and ice in the NH, which in turn increases the albedo. And over time, this feedback drives the average global temperature lower, by greatly increasing the average global albedo.

Note that we don’t need CO2 to explain any of that … and yet, in your words, it is able to “convert a local change in insolation to a world-wide change in temperature”, something you claim is not explainable other than by CO2.

The sequence of events during terminations III and IV is the same as that previously observed for terminations I and II. Vostok temperature, CO2 and CH4 increase in phase during terminations. Uncertainty in the phasing comes mainly from the sampling frequency and the ubiquitous uncertainty in gas-age/ice-age differences (which are well over +/-1 kyr during glaciations and terminations). In a recent paper, Fischer et al.44 present a CO2 record, from Vostok core, spanning the past three glacial terminations. They conclude that CO2 concentration increases lagged Antarctic warmings by 600 +/- 400 years. However, considering the large gas-age/iceage uncertainty (1,000 years, or even more if we consider the accumulation-rate uncertainty), we feel that it is premature to infer the sign of the phase relationship between CO2 and temperature at the start of terminations. We also note that their discussion relates to early deglacial changes, not the entire transitions.

So Petit et al 1999 basically says you can’t tell whether CO₂ lags, leads, or is in phase with the temperature rise at the start of the terminations. Yet you have determined Petit et al 1999 is showing CO₂ was lagging the temperature in the Antarctic, and by extension the Southern Hemisphere, during glacial terminations. Where did you get this?

For Caillon et al 2003, you should have included more of the abstract:

The analysis of air bubbles from ice cores has yielded a precise record of atmospheric greenhouse gas concentrations, but the timing of changes in these gases with respect to temperature is not accurately known because of uncertainty in the gas age–ice age difference. We have measured the isotopic composition of argon in air bubbles in the Vostok core during Termination III (~240,000 years before the present). This record most likely reflects the temperature and accumulation change, although the mechanism remains unclear. The sequence of events during Termination III suggests that the CO2 increase lagged Antarctic deglacial warming by 800 +/1 200 years and preceded the Northern Hemisphere deglaciation.

So they start by saying the CO₂ to temperature timing relationship is too uncertain to determine, except they think they’ve got it by looking at the argon isotopes, but they can’t provide a valid mechanism to explain it.

Moreover, from publication pg 1730, pdf pg 3, mentioning methane, comes the important part concerning the timing between the hemispheres:

The sudden increase of 150 ppbv practically coeval with the 𝛿⁴⁰Ar maximum would be linked to the main deglaciation, thus indicating that Vostok temperature began warming ~6000 years (Fig. 3) before the associated warming in the Northern Hemisphere (1).

So here’s the big timeline:

1. Antarctica (and the Southern Hemisphere by extension) begins warming at the start of the glaciation termination.
2. CO₂ starts rising about 800 years later.
3. About 6000 years later after Antarctica starts warming, the Northern Hemisphere begins warming as well.

So “CO₂ leads warming in the Northern Hemisphere” since the NH starts warming so much later after the SH warming and the subsequent CO₂ increase.

The temperature increase at Antarctica, and by extension the Southern Hemisphere, leads all. And CO₂ comes off as a bit player in later warming, at most.

To the best of our knowledge, deglaciation events are triggered by changes in insolation from lower to higher latitudes. The warming is not limited to the regions receiving more insolation, but is global. Both poles AND the sub-tropics and tropics all warm up at around the same time. If not well-mixed CO2, what mechanisms, in the minds of critics, are supposed to convert a local change in insolation to a world-wide change in temperature? Unless someone has a good theory about how the whole world heats up from insolation changes in specific regions, then it’s obvious that CO2 rise will lead temps in some parts of the world during transitions. It just makes sense.

By the sources you have offered, both poles and the sub-tropics and the tropics are not warming up at the same time. There is more than enough time for ocean currents to spread around the Southern warmth, for the SH glacial sheets to shrink and go away, with the NH ones following, leading to the albedo changes that allow more insolation. But CO₂ increases would lead temperature increases in some parts of the world, by coincidence.

The trigger for glacial changes (in the quaternary period) is orbital variations. CO2 responds. But it also amplifies and leads. 1;ma630, there is no binary logic that requires only one or the other to happen. Both may, and apparently, both have. I am of the understanding that thoughtful skeptics
at WUWT do not deny the radiative properties of CO2 in the atmosphere, so there should be no bar to the notion thar CO2 acts as a feedback and leads temps in some parts of the world.

Remember, too, that the insolation change is a very weak forcing. The solar intensity itself does not change, it is only that the point of focus (insolation) changes. It is the system of feedbacks that increases the power of localised changes, and makes those changes global.

kadaka,

I was responding to the notion that this study refuted previous work. It does not. Petit and Caillion speculate on the processes, and both studies indicate CO2 both lagging and leading temperature change and deglaciation, in line with this study. There are differences between the papers, but the basic point on lag/lead, the one that has got people here incensed, is no turnaround. It is an extension and a refinement of an older idea. No doubt further investigation will come up with slightly different timings and weighting of various feedbacks.

But CO₂ increases would lead temperature increases in some parts of the world, by coincidence.

You seem to believe that CO2 has no radiative property that could enhance warming. I doubt I could change your mind about that.

I’m not sure that you realised I was talking about deglaciation periods – the change from glacial to interglacial. The transition I focussed on has sharper and more pertinent characteristics (ie, warming) for the general debate.

But the point would be the same in each direction. I’ll apply it now to the onset of an ice age, per your reply.

If insolation tracks from high latitudes to low over the millennial orbital variation, one would expect that the high latitudes would get slightly cooler, and the lower latitudes would get slightly warmer all else being equal. Even while the polar ice sheets extend, increasing albedo in those regions, and high latitude oceans cool, low latitude oceans and landmasses should warm. But what happens is that the entire globe changes temperature in the same direction. Therefore, other processes must amplify and extend the initial weak, localised forcing. Some deeper process/es convey the temperature change occuring in the high latitudes to the entire globe, sufficient to counteract the insolation forcing in the opposite direction (at low latitudes in this glaciation example). As CO2 is well-mixed in the atmosphere, it is an obvious candidate for making a regional effect global. And indeed, the amplifying response of GHGs to insolation changes over Milankovitch cycles is consistent across all studies of late quaternary ice age transitions that consider these factors, not just this latest study. Of course, there are other processes at play (aerosols, dust, vegetation changes, ocean and atmospheric circulation, cloudiness etc), there is uncertainty in the data, and the details and timings will continue to be investigated. But there seems to be little uncertainty that CO2 both lags and leads (amplifies) temperature changes in the geologic record. This has been a consistent understanding for more than a decade, a standard rebuttal from mainstreamer blogs for nearly as long, and easily discovered in older studies of ice age transitions. (How have the skeptics missed it?)

The focus on ice age transitions has corrollary value. Late quaternary ice age shifts (as well as LIA, volcanic eruptions and other data-based estimates of climate sensitivity), is one source of observationally based climate sensitivity estimates. No GCMs are required here, just simple equations. And no need to factor in tectonic redistribution or solar variance. The arrangement of the continents and associated heat flows are consistent for the late quaternary period, as is solar output (no ‘faint sun’ paradox to deal wth). We can compare apples with apples.

barry says:
April 10, 2012 at 7:29 pm
The transition I focussed on has sharper and more pertinent characteristics (ie, warming) for the general debate.
If insolation tracks from high latitudes to low over the millennial orbital variation, one would expect that the high latitudes would get slightly cooler, and the lower latitudes would get slightly warmer all else being equal. Even while the polar ice sheets extend, increasing albedo in those regions, and high latitude oceans cool, low latitude oceans and landmasses should warm. But what happens is that the entire globe changes temperature in the same direction.
Some deeper process/es convey the temperature change occuring in the high latitudes to the entire globe, sufficient to counteract the insolation forcing in the opposite direction (at low latitudes in this glaciation example).
… the amplifying response of GHGs to insolation changes over Milankovitch cycles is consistent across all studies of late quaternary ice age transitions that consider these factors, not just this latest study.

It may be that the frequencies of Milankovitch have relations to the terrestrial temperature proxy frequencies, but because the functions of the the Milankovitch oscillations have sinusoid character there is a general problem, to explain a varying physical heat process of a saw tooth oscillation from Vostok. Moreover, there is a problem to explain the geometry of an oscillator with a main frequency of 1/94300 y^-1. A frequency of 1.406 hours^-1 is related to the geometry of the radius/accelaration of the Earth, and for such low frequencies it needs greater geometries like the Sun. If you take a resonance mode of n=2 and a solar photon diffusion time of ½ * 377134 years you get a cycle time of 94284 years [t (y) = pow(2,-2) * 377134]. This is an idea of Robert Ehrlich using the FFT data from Bolshakow.

I have synthesised some Vostok saw tooth frequencies using the their mode power and it fits good with the (slightly time scaled) Vostok spectra over 1 Million years.

The focus on ice age transitions has corrollary value. Late quaternary ice age shifts (as well as LIA, volcanic eruptions and other data-based estimates of climate sensitivity), is one source of observationally based climate sensitivity estimates. No GCMs are required here, just simple equations. And no need to factor in tectonic redistribution or solar variance. The arrangement of the continents and associated heat flows are consistent for the late quaternary period, as is solar output (no ‘faint sun’ paradox to deal wth). We can compare apples with apples.

If it is rue, that there are low frequency modes in the Sun it remains unclear to what the main phase is coupled. But regarding the more faster heat frequencies observed on the globe, it is evident, that the frequencies are related to solar tide functions from (outer sun) planet couples.

Also the nature of the function has changed; the variations have lost their saw tooth character, and have changed to a complex triangle characteristic.

While the frequencies of the Vostok data seems to be related to the inner Sun only, the fact that the solar tide functions can be directed to planetary couples there remains neither any molecule idea nor a terrestrial local heat source to explain the temperature spectra in high time resolution. This is shown especially in this graph:

There is no relevant time constant between the solar tide function of 11 planets and the UAH global temperature function.

you have been critized for not showing your methods, but your forecast of “major quakes are likelely to come in the present period (~8-10th) ” has been met by the 8.5+ Sumatra quake of today morning. When reading this news, I remembered to have read your forecast here in this thread a few days ago, hence this otherwise off-topic remark.

Ditto Hugo M – Piers Corbyn has correctly predicted a major earthquake (somewhere in the world, not at a specific location). This lends credence for his hypotheses about influence of solar wind and magnetic fields etc on climate and tectonic events.

I was responding to the notion that this study refuted previous work. It does not. Petit and Caillion speculate on the processes, and both studies indicate CO2 both lagging and leading temperature change and deglaciation, in line with this study. (…)

Note she also used for “references & more info” your two mentioned sources:
“Petit et all 1999 — analysed 420,000 years of Vostok, and found that as the world cools into an ice age, the delay before carbon falls is several thousand years.”
“Caillon et al 2003 analysed the Vostok data and found a lag (where CO2 rises after temperature) of 800 ± 200 years.”

First off, Shakun et al 2012, per the title, analyzes the last deglaciation. Caillon et al 2003 analyzes Termination III, which is not the last deglaciation but the one preceding it, thus was not relevant.

That leaves Petit et al 1999, which as I’ve previously mentioned decided it can’t be determined which comes first at the start of deglaciation.

So neither of your sources indicate what you said they did in regards to this study (Shakun et al 2012).

Later you said, and I’ll include the same bit of my comment as you included it:

But CO₂ increases would lead temperature increases in some parts of the world, by coincidence.

You seem to believe that CO2 has no radiative property that could enhance warming. I doubt I could change your mind about that.

What I do believe is you likely have a profound ignorance of my previous writings on this site. Granted that when painting with such a broad brush, it is common to paint all skeptics with what “the opposition” promotes as the standard “denialist” color set, which includes denying CO₂ has a “…radiative property that could enhance warming.”

In reality, very few skeptics would claim CO₂ is not a greenhouse gas, and we tend to “police our own” and rebuke those who would do so. I, along with almost all skeptics, recognize this property while acknowledging, as the real-world data shows, that water vapor is the dominant GHG, that the posited positive feedbacks that are to amplify CO₂’s effect to catastrophic levels are non-existent in reality, and negative feedbacks that dampen global warming exist and their actions are the rule that controls global temperatures as in the current interglacial.

The “earlier understanding” is the ~800 year lag between temperature rise and CO₂ rise, as famously graphed on Jo Nova’s site “…from 420,000 years to 5,000 years before the present.”:

It’s good that you point out the Jo Nova article (and that you are willing to include several glacial transitions instead of just the one examined by Shakun). Skepticalscience dealt with her take in 2010 – 18 months ago. At that time, more than a year before the Shakun paper came out, they said;

Ice cores and marine sediments find that initial warming begins in Antarctica. Around 800 years later, CO2 rises and at the same time, warming spreads to the tropics and northern hemisphere (Cuffey 2001, Caillon 2003, Stott 2007).

How did they manage to guess what Shakun would write a year and a half later?

They didn’t. They are simply familiar with the science (they cite Caillion, amongst others). I would criticise theit blog post, however, because it does not reflect uncertainty and nuance in the science.

You are trying to wish away what Caillion and Petit said. They highlight uncertainty, they speak of alternative timings. But included in their analyses is the suggestion that CO2 led in the North (as I quoted – it’s pretty plain in their text). Suggestions of CO2 lagging and leading glacial transitions are dotted throughout the literature.

Examination of phase relationships shows that atmospheric carbon dioxide concentration leads ice volume over the orbital bandwidth, and is forced by orbital changes through a mechanism, at present not fully understood, with a short response time […] variations in atmospheric CO2 should be regarded as part of the forcing of ice volume changes

1998 – “The Sequence of Events Surrounding Termination II and their Implications for the Cause of Glacial/Interglacial CO2 Changes” – Broecker and Henderson

The synchronous change of atmospheric CO2 and southern hemisphere temperature thus preceded the melting of the northern hemisphere ice sheets

<blockquote.The CO2 increase in interval I, which occurred before any substantial warming in the Northern Hemisphere, is consistent with the present view of the role of the Southern Hemisphere for causing the CO2 increase.

For different Milankovitch events (41K period), the same principle may apply from North to South.

2006 – “Orbital changes and climate” – Ruddiman

At the 41-K cycle, most northern hemisphere responses have the late phase of northern ice sheets, and southern-hemisphere responses are dominated or strongly influenced by a CO2 signal transferred from the north carrying the same phase as the ice sheets (Fig. 4). At the 41-K cycle, greenhouse feedback thus tends to keep the two hemispheres in phase.

Shakun et al have not departed from previous understanding. The notion that CO2 lags at all times and in all places during glacial transitions is peculiar to some in the skeptic camp, who appeared to have favoured a soundbyte over learning about ice age transition processes.

Far more papers than I’ve noted above agree that the CO2 feedback is required to explain a singificant amount of global temperature and ice sheet change during glacial transitions. This
is so for Petit, Cailiion and the other papers cited by Jo Nova. If I close one eye and squint through the other, tilt my head a bit and skim, I just might be able to come away with the impression that the literature only ever mentions CO2 lagging temperature rises, and that CO2 changes have no impact during glacial transitions.

“If I close one eye and squint through the other, tilt my head a bit and skim, I just might be able to come away with the impression that the literature only ever mentions CO2 lagging temperature rises, and that CO2 changes have no impact during glacial transitions.”

Then you’re doing it wrong. And Willis has effectively deconstructed Shakun et al. in several incisive articles. To put it bluntly, Shakun’s paper is cherry-picked crap.

CO2 also lags temperature in the Greenland cores. So all this south-north stuff is hogwash.

What Shakun et al. are doing is the “Younger Dryas two step”. They take advantage of the fact that in the YD cold interval, temperatures fell but (interestingly) CO2 did not. They exploit the fact that there were two temperature rises, before and after the YD, but only one CO2 rise.

This is because the overall rise in temps from glacial to interglacial was ocean driven, thus it leaves a CO2 signature, while the YD was likely an atmosphere driven event due to volcanism or an impact of some sort. You will find that ocean driven temperature changes drive CO2 changes while atmosphere driven temperature change does not so much.

In the other transitions, interglacial to glacial, the lag of CO2 is much larger – too large for even Shakun to sweep under the carpet. Does CO2 amplification only work with increasing temperatures, not decreasing? Why did CO2 not fall during the YD? Why did CO2 rise in the latter half of the Holocene while temperatures fell?

This idea that CO2 first follows temperature rises caused by Milankovich orbital changes (although soon no doubt even Milankovich – not being in the cosy Anglosaxon family of the core AGW elite and with a scary east-european name – will be airbrushed out in favour of fire-lighting antics of protohumans and australopithecines, mammoth farting, etc..) is the most flagrant and absurd breach of Occam’s razor (and Occam is even nice and English!). CO2 follows then amplifies then leads? Pull the other one! If this were so then there would be an exponential form to temperature rises, which there is not.

CO2 also lags temperature in the Greenland cores. So all this south-north stuff is hogwash.

Well, you could be right. I didn’t think the science was settled owing to problems with Greenland ice cores (as different to SH cores which are very clean), but perhaps your insight is keener or more up to date. Can you cite a couple of studies which settle this matter – in such a way that there is no longer any doubt? I’d genuinely like to learn of such.

But whatever the case, it’s beside the point I was making. Has anyone suggested that CO2 leads in any part of glacial transitions prior to Shakun et al? Yes, they have. There are other interpretations of glacial transitions that do not discuss a CO2 lead, or assign less weight to GHG feedbacks than most studies, but the point is that Shakun’s ideas are not new in any way (including the role of ocean circulation), and the surprise and outrage hinging on such a supposition are misinformed and misplaced. All you have to do is read the literature (for instance, the half dozen or so examples I cited above).

The main difference between Shakun and previous studies is that Shakun et al incorporate more data from a greater variety of locations. On the surface, that would seem like a good idea.

barry is beating a dead horse. The Shakun paper is crap. No one really bothered to review it because it said what they wanted to hear. It’s still cherry-picked crap; worthless as science and only good for alarmist propaganda.

Willis:
Congrats on an excellent deconstruction of a shaky (pun intended) and deceptive reconstruction! Something that caught my attention is the rise in CO2 in the early Holocene that you figured out and plotted in Figure 2 above. I’d noticed the same phenomenon in some other data I’d seen, and mentioned it in a book I wrote and self-published on global warming (Global Warming False Alarm) a few years ago. In the book, I pointed out that the continued rise of CO2 after the global temperature had leveled out after the last ice age is completely inconsistent with the AGW belief that today’s rising CO2 has caused global warming. Am now working on a 2nd edition of the book – would be glad to send you a copy when it’s finished.

Here is yet another paper that posits Southern warming and CO2 rise leading Northern warming.

Full abstract:

The Earth became warmer and cooler during the ice ages along with changes in the Earth’s orbit, but the orbital changes themselves are not nearly large enough to explain the magnitude of the warming and cooling. Atmospheric CO2 also rose and fell, but again, the CO2 changes are rather small in relation to the warming and cooling. So, how did the Earth manage to warm and cool by so much? Here we argue that, for the big transitions at least, the Earth did not warm and cool as a single entity. Rather, the south warmed instead at the expense of a cooler north through massive redistributions of heat that were set off by the orbital forcing. Oceanic CO2 was vented up to the atmosphere by the same redistributions. The north then warmed later in response to higher CO2 and a reduced albedo from smaller ice sheets. This form of north/south displacement is actually very familiar, as it is readily observed during the Younger Dryas interval 13,000 years ago and in the various millennial‐scale events over the last 90,000 years.

Thanks for drawing my attention to that paper by Toggweiler and Lea. However, if you look very carefully at their Figure 1, which compares the CO2 level to both Antarctic and Greenland temperatures, you’ll find that CO2 not only lags temperature in the Antarctic, but also (just) in the Northern hemisphere. I agree that the conclusion about the seesaw effect between the two hemispheres is the same as Shakun’s, but the two papers are not saying the same thing about the CO2 lag.

And the ‘hide the decline’ is embarrassing to the AGW ‘cause’. It seems the embarrassment is so great that supporters of the cause don’t want to discuss it. Indeed, they even prefer to discuss Shakun’s junk science as a method to avoid discussing the subject of this thread.

not just the paper I have cited but a number of others have posited the same general conslcusion as Shakun et al, whose general description of glacial termination is that the Southern warming caused CO2 rise, which then spread the warming to the North. From the paper I’ve just quoted, we don’t need to eye-ball graphs and make guesses abouit pixels – we can read what the authors themselves say.

Here we argue that, for the big transitions at least, the Earth did not warm and cool as a single entity. Rather, the south warmed instead at the expense of a cooler north through massive redistributions of heat that were set off by the orbital forcing. Oceanic CO2 was vented up to the atmosphere by the same redistributions. The north then warmed later in response to higher CO2 and a reduced albedo from smaller ice sheets.

That is as clear as can be. We don’t need to reinterpret.

I am not arguing that this has definitely been the process during glacial terminations, just that Shakun et al do not overturn previous hypotheses. The excitement in the skeptical milieu comes from a shallow understanding of the science. It’s not that the paper has said anything new, it’s just said it more plainly, and thus more directly confronted a canard in the general debate.

Barry:
I’d seen that statement in the abstract of the paper you cited, but my interpretation of the paper is that the Northern response to CO2 (where CO2 led) was very slow – tens of thousands of years, much longer than the 600 years or so lag of CO2 in Antarctica. Shakun et al are saying that the CO2 lead at the end of the last ice age was only 460 yr globally, 720 yr in the Northern hemisphere.

It seems to me that the two papers are very different in this respect, although I have to agree that the underlying idea is similar. Even Skakun at al refer to Toggweiler and Lea’s conclusion as CO2 being “largely a consequence rather than cause of past climate change”. But of course they wanted to push their own paper, so that may not be an objective statement.

As I mentioned in an earlier post, I’m revising the book I wrote on global warming three years ago. The Shakun et al paper caught my attention as I’m currently working on a section titled “Two-faced CO2” in a chapter on climate sensitivity. As I’m not a climate scientist (though a PhD in Physics), I want to be extra sure I have my facts correct. While I’ve read a number of the papers in this area, I’m sure you know more about the subject than I do. Thanks for all your comments.